1
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García-Arroyo P, Gala E, Martínez-Fernández M, Salagre E, Martínez JI, Michel EG, Segura JL. Turn-On Solid-State Fluorescent Determination of Zinc Ion by Quinoline-Based Covalent Organic Framework. Macromol Rapid Commun 2024:e2400134. [PMID: 38689427 DOI: 10.1002/marc.202400134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 04/22/2024] [Indexed: 05/02/2024]
Abstract
A new quinoline-based COF (covalent organic framework), obtained by Povarov reaction, containing 2,6-diisopropylphenyl moieties as substituents over the heterocyclic ring is described for detecting Zn2+ in aqueous solution. The introduction of the mentioned bulky phenyl rings into the network favors an increase of the distance between the reticular sheets and their arrangement, obtaining a new material with an alternating AB type stacking. The new material exhibits good selectivity to detect Zn2+ by fluorescence emission in aqueous solutions up to a concentration of 1.2 × 10-4 m of the metal ion. In order to have a deeper insight into the interaction between the COF and the zinc cation, a thorough spectroscopical, microscopical, and theoretical study is also presented and discussed in this communication.
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Affiliation(s)
- Paloma García-Arroyo
- Departamento de Química Orgánica I, Facultad de CC. Químicas, Universidad Complutense de Madrid, Madrid, 28040, Spain
| | - Elena Gala
- Departamento de Química Orgánica I, Facultad de CC. Químicas, Universidad Complutense de Madrid, Madrid, 28040, Spain
- Chemical and Environmental Technology Department, Rey Juan Carlos University, Móstoles, 28933, Spain
| | - Marcos Martínez-Fernández
- Departamento de Química Orgánica I, Facultad de CC. Químicas, Universidad Complutense de Madrid, Madrid, 28040, Spain
| | - Elena Salagre
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, 28049, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, 28049, Spain
| | - José I Martínez
- Departamento de Materiales de baja dimensionalidad, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Madrid, 28049, Spain
| | - Enrique G Michel
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, 28049, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, 28049, Spain
| | - José L Segura
- Departamento de Química Orgánica I, Facultad de CC. Químicas, Universidad Complutense de Madrid, Madrid, 28040, Spain
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2
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Guo H, Jiménez-Sánchez MD, Michel EG, Martínez-Galera AJ, Gómez-Rodríguez JM. Aperiodic Modulation of Graphene Driven by Oxygen-Induced Reconstruction of Rh(110). J Phys Chem C Nanomater Interfaces 2023; 127:17930-17938. [PMID: 37744964 PMCID: PMC10513088 DOI: 10.1021/acs.jpcc.3c02643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 08/04/2023] [Indexed: 09/26/2023]
Abstract
Artificial nanostructuring of graphene has served as a platform to induce variations in its structural and electronic properties, fostering the experimental observation of a wide and fascinating phenomenology. Here, we present an approach to graphene tuning, based on Rh(110) surface reconstruction induced by oxygen atoms intercalation. The resulting nanostructured graphene has been characterized by scanning tunneling microscopy (STM) complemented by low-energy electron microscopy (LEEM), micro low-energy electron diffraction (μ-LEED), micro angle-resolved photoemission spectroscopy (μ-ARPES), and micro X-ray photoelectron spectroscopy (μ-XPS) measurements under ultrahigh vacuum (UHV) conditions at room temperature (RT). It is found that by fine-tuning the O2 exposure amount, a mixture of missing row surface reconstructions of the metal surface below the graphene layer can be induced. This atomic rearrangement under the graphene layer results in aperiodic patterning of the two-dimensional (2D) material. The electronic structure of the resulting nanostructured graphene is dominated by a linear dispersion of the Dirac quasiparticles, characteristic of its free-standing state but with a p-doping character. The local effects of the underlying missing rows on the interfacial chemistry and on the quasiparticle scattering processes in graphene are studied using atomically resolved STM images. The possibilities offered by this nanostructuring approach, which consists in inducing surface reconstructions under graphene, could provide a novel tuning strategy for this 2D material.
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Affiliation(s)
- Haojie Guo
- Departamento
de Física de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | | | - Enrique G. Michel
- Departamento
de Física de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
- Instituto
Nicolás Cabrera, Universidad Autónoma
de Madrid, E-28049 Madrid, Spain
- Condensed
Matter Physics Center (IFIMAC), Universidad
Autónoma de Madrid, E-28049 Madrid, Spain
| | - Antonio J. Martínez-Galera
- Instituto
Nicolás Cabrera, Universidad Autónoma
de Madrid, E-28049 Madrid, Spain
- Departamento
de Física de Materiales, Universidad
Autónoma de Madrid, E-28049 Madrid, Spain
| | - José M. Gómez-Rodríguez
- Departamento
de Física de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
- Instituto
Nicolás Cabrera, Universidad Autónoma
de Madrid, E-28049 Madrid, Spain
- Condensed
Matter Physics Center (IFIMAC), Universidad
Autónoma de Madrid, E-28049 Madrid, Spain
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3
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Salagre E, Segovia P, González-Barrio MÁ, Jugovac M, Moras P, Pis I, Bondino F, Pearson J, Wang RS, Takeuchi I, Fuller EJ, Talin AA, Mascaraque A, Michel EG. Physical Delithiation of Epitaxial LiCoO 2 Battery Cathodes as a Platform for Surface Electronic Structure Investigation. ACS Appl Mater Interfaces 2023. [PMID: 37466037 PMCID: PMC10401565 DOI: 10.1021/acsami.3c06147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
We report a novel delithiation process for epitaxial thin films of LiCoO2(001) cathodes using only physical methods, based on ion sputtering and annealing cycles. Preferential Li sputtering followed by annealing produces a surface layer with a Li molar fraction in the range 0.5 < x < 1, characterized by good crystalline quality. This delithiation procedure allows the unambiguous identification of the effects of Li extraction without chemical byproducts and experimental complications caused by electrolyte interaction with the LiCoO2 surface. An analysis by X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) provides a detailed description of the delithiation process and the role of O and Co atoms in charge compensation. We observe the simultaneous formation of Co4+ ions and of holes localized near O atoms upon Li removal, while the surface shows a (2 × 1) reconstruction. The delithiation method described here can be applied to other crystalline battery elements and provide information on their properties that is otherwise difficult to obtain.
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Affiliation(s)
- Elena Salagre
- Dto. Física Materia Condensada, Univ. Autónoma de Madrid, 28049 Madrid, Spain
| | - Pilar Segovia
- Dto. Física Materia Condensada, Univ. Autónoma de Madrid, 28049 Madrid, Spain
- IFIMAC (Condensed Matter Physics Center), Univ. Autónoma de Madrid, 28049 Madrid, Spain
| | | | - Matteo Jugovac
- Istituto di Struttura della Materia-CNR (ISM-CNR), Trieste 34149, Italy
| | - Paolo Moras
- Istituto di Struttura della Materia-CNR (ISM-CNR), Trieste 34149, Italy
| | - Igor Pis
- IOM CNR Laboratorio TASC, AREA Science Park, Trieste 34149, Italy
| | - Federica Bondino
- IOM CNR Laboratorio TASC, AREA Science Park, Trieste 34149, Italy
| | - Justin Pearson
- Materials Science and Engineering, Univ. of Maryland, College Park, Maryland 20742, United States
| | - Richmond Shiwei Wang
- Materials Science and Engineering, Univ. of Maryland, College Park, Maryland 20742, United States
| | - Ichiro Takeuchi
- Materials Science and Engineering, Univ. of Maryland, College Park, Maryland 20742, United States
| | - Elliot J Fuller
- Sandia National Laboratories, 7011 East Avenue, Livermore, California 94550, United States
| | - Alec A Talin
- Sandia National Laboratories, 7011 East Avenue, Livermore, California 94550, United States
| | - Arantzazu Mascaraque
- Dto. Física de Materiales, Fac. Ciencias Físicas, Univ. Complutense de Madrid, 28040 Madrid, Spain
| | - Enrique G Michel
- Dto. Física Materia Condensada, Univ. Autónoma de Madrid, 28049 Madrid, Spain
- IFIMAC (Condensed Matter Physics Center), Univ. Autónoma de Madrid, 28049 Madrid, Spain
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4
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Guillem-Navajas A, Martín-Illán JÁ, Salagre E, Michel EG, Rodriguez-San-Miguel D, Zamora F. Iron Oxyhydroxide-Covalent Organic Framework Nanocomposite for Efficient As(III) Removal in Water. ACS Appl Mater Interfaces 2022; 14:50163-50170. [PMID: 36282943 PMCID: PMC9827450 DOI: 10.1021/acsami.2c14744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 10/12/2022] [Indexed: 06/16/2023]
Abstract
The presence of heavy metal ions in water is an environmental issue derived mainly from industrial and mineral contamination. Metal ions such as Cd(II), Pb(II), Hg(II), or As(III) are a significant health concern worldwide because of their high toxicity, mobility, and persistence. Covalent organic frameworks (COFs) are an emerging class of crystalline organic porous materials that exhibit very interesting properties such as chemical stability, tailored design, and low density. COFs also allow the formation of composites with remarkable features because of the synergistic combination effect of their components. These characteristics make them suitable for various applications, among which water remediation is highly relevant. Herein, we present a novel nanocomposite of iron oxyhydroxide@COF (FeOOH@Tz-COF) in which lepidocrocite (γ-FeOOH) nanorods are embedded in between the COF nanoparticles favoring As(III) remediation in water. The results show a remarkable 98.4% As(III) uptake capacity in a few minutes and impressive removal efficiency in a wide pH range (pH 5-11). The chemical stability of the material in the working pH range and the capability of capturing other toxic heavy metals such as Pb(II) and Hg(II) without interference confirm the potential of FeOOH@Tz-COF as an effective adsorbent for water remediation even under harsh conditions.
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Affiliation(s)
- Ana Guillem-Navajas
- Departamento
de Química Inorgánica, Facultad de Ciencias, Institute for Advanced Research in Chemical Sciences
(IAdChem) and Condensed Matter Physics Institute (IFIMAC), Universidad
Autónoma de Madrid, Madrid 28049, Spain
| | - Jesús Á. Martín-Illán
- Departamento
de Química Inorgánica, Facultad de Ciencias, Institute for Advanced Research in Chemical Sciences
(IAdChem) and Condensed Matter Physics Institute (IFIMAC), Universidad
Autónoma de Madrid, Madrid 28049, Spain
| | - Elena Salagre
- Departamento
de Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid 28048, Spain
| | - Enrique G. Michel
- Departamento
de Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid 28048, Spain
- Condensed
Matter Physics Center (IFIMAC), Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid 28048, Spain
| | - David Rodriguez-San-Miguel
- Departamento
de Química Inorgánica, Facultad de Ciencias, Institute for Advanced Research in Chemical Sciences
(IAdChem) and Condensed Matter Physics Institute (IFIMAC), Universidad
Autónoma de Madrid, Madrid 28049, Spain
| | - Félix Zamora
- Departamento
de Química Inorgánica, Facultad de Ciencias, Institute for Advanced Research in Chemical Sciences
(IAdChem) and Condensed Matter Physics Institute (IFIMAC), Universidad
Autónoma de Madrid, Madrid 28049, Spain
- Condensed
Matter Physics Center (IFIMAC), Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid 28048, Spain
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5
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Sierra L, Gibaja C, Torres I, Salagre E, Avilés Moreno JR, Michel EG, Ocón P, Zamora F. Alpha-Germanium Nanolayers for High-Performance Li-ion Batteries. Nanomaterials (Basel) 2022; 12:3760. [PMID: 36364534 PMCID: PMC9655185 DOI: 10.3390/nano12213760] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 10/20/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
The exfoliation of tridimensional crystal structures has recently been considered a new source of bidimensional materials. The new approach offers the possibility of dramatically enlarging the library of bidimensional materials, but the number of nanolayers produced so far is still limited. Here, we report for the first time the use of a new type of material, α-germanium nanolayers (2D α-Ge). The 2D α-Ge is obtained by exfoliating crystals of α-germanium in a simple one-step procedure assisted by wet ball-milling (gram-scale fabrication). The α-germanium nanolayers have been tested as anode material for high-performance LIBs. The results show excellent performance in semi-cell configuration with a high specific capacity of 1630 mAh g-1 for mass loading of 1 mg cm-2 at 0.1 C. The semi-cell was characterized by a constant current rate of 0.5 C during 400 cycles and different scan rates (0.1 C, 0.5 C, and 1 C). Interestingly, the structural characterization, including Raman spectroscopy, XRPD, and XPS, concludes that 2D α-Ge largely retains its crystallinity after continuous cycling. These results can be used to potentially apply these novel 2D germanium nanolayers to high-performance Li-ion batteries.
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Affiliation(s)
- Laura Sierra
- Departamento de Química Física Aplicada, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Carlos Gibaja
- Departamento de Química Inorgánica, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Iñigo Torres
- Departamento de Química Inorgánica, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Elena Salagre
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | | | - Enrique G. Michel
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Pilar Ocón
- Departamento de Química Física Aplicada, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Félix Zamora
- Departamento de Química Inorgánica, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
- IMDEA-Nanociencia, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain
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6
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Fuller EJ, Ashby DS, Polop C, Salagre E, Bhargava B, Song Y, Vasco E, Sugar JD, Albertus P, Menteş TO, Locatelli A, Segovia P, Gonzalez-Barrio MÁ, Mascaraque A, Michel EG, Talin AA. Imaging Phase Segregation in Nanoscale Li xCoO 2 Single Particles. ACS Nano 2022; 16:16363-16371. [PMID: 36129847 DOI: 10.1021/acsnano.2c05594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
LixCoO2 (LCO) is a common battery cathode material that has recently emerged as a promising material for other applications including electrocatalysis and as electrochemical random access memory (ECRAM). During charge-discharge cycling LCO exhibits phase transformations that are significantly complicated by electron correlation. While the bulk phase diagram for an ensemble of battery particles has been studied extensively, it remains unclear how these phases scale to nanometer dimensions and the effects of strain and diffusional anisotropy at the single-particle scale. Understanding these effects is critical to modeling battery performance and for predicting the scalability and performance of electrocatalysts and ECRAM. Here we investigate isolated, epitaxial LiCoO2 islands grown by pulsed laser deposition. After electrochemical cycling of the islands, conductive atomic force microscopy (c-AFM) is used to image the spatial distribution of conductive and insulating phases. Above 20 nm island thicknesses, we observe a kinetically arrested state in which the phase boundary is perpendicular to the Li-planes; we propose a model and present image analysis results that show smaller LCO islands have a higher conductive fraction than larger area islands, and the overall conductive fraction is consistent with the lithiation state. Thinner islands (14 nm), with a larger surface to volume ratio, are found to exhibit a striping pattern, which suggests surface energy can dominate below a critical dimension. When increasing force is applied through the AFM tip to strain the LCO islands, significant shifts in current flow are observed, and underlying mechanisms for this behavior are discussed. The c-AFM images are compared with photoemission electron microscopy images, which are used to acquire statistics across hundreds of particles. The results indicate that strain and morphology become more critical to electrochemical performance as particles approach nanometer dimensions.
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Affiliation(s)
- Elliot J Fuller
- Sandia National Laboratories, 7011 East Avenue, Livermore, California 94550, United States
| | - David S Ashby
- Sandia National Laboratories, 7011 East Avenue, Livermore, California 94550, United States
| | - Celia Polop
- Departamento de Física de la Materia Condensada and Instituto Universitario de Ciencia de Materiales Nicolás Cabrera (INC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
- IFIMAC (Condensed Matter Physics Center), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Elena Salagre
- Departamento de Física de la Materia Condensada and Instituto Universitario de Ciencia de Materiales Nicolás Cabrera (INC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Bhuvsmita Bhargava
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20740, United States
| | - Yueming Song
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20740, United States
| | - Enrique Vasco
- Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas (CSIC), Sor Juana Inés de la Cruz 3, 28049 Madrid, Spain
| | - Joshua D Sugar
- Sandia National Laboratories, 7011 East Avenue, Livermore, California 94550, United States
| | - Paul Albertus
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20740, United States
| | | | | | - Pilar Segovia
- Departamento de Física de la Materia Condensada and Instituto Universitario de Ciencia de Materiales Nicolás Cabrera (INC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
- IFIMAC (Condensed Matter Physics Center), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | | | - Arantzazu Mascaraque
- Departamento de Física de Materiales, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Enrique G Michel
- Departamento de Física de la Materia Condensada and Instituto Universitario de Ciencia de Materiales Nicolás Cabrera (INC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
- IFIMAC (Condensed Matter Physics Center), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - A Alec Talin
- Sandia National Laboratories, 7011 East Avenue, Livermore, California 94550, United States
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7
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Salagre E, Quílez S, de Benito R, Jaafar M, van der Meulen HP, Vasco E, Cid R, Fuller EJ, Talin AA, Segovia P, Michel EG, Polop C. A multi-technique approach to understanding delithiation damage in LiCoO 2 thin films. Sci Rep 2021; 11:12027. [PMID: 34103560 PMCID: PMC8187655 DOI: 10.1038/s41598-021-91051-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 05/17/2021] [Indexed: 11/22/2022] Open
Abstract
We report on the delithiation of LiCoO2 thin films using oxalic acid (C2H2O4) with the goal of understanding the structural degradation of an insertion oxide associated with Li chemical extraction. Using a multi-technique approach that includes synchrotron radiation X-ray diffraction, scanning electron microscopy, micro Raman spectroscopy, photoelectron spectroscopy and conductive atomic force microscopy we reveal the balance between selective Li extraction and structural damage. We identify three different delithiation regimes, related to surface processes, bulk delithiation and damage generation. We find that only a fraction of the grains is affected by the delithiation process, which may create local inhomogeneities. However, the bulk delithiation regime is effective to delithiate the LCO film. All experimental evidence collected indicates that the delithiation process in this regime mimics the behavior of LCO upon electrochemical delithiation. We discard the formation of Co oxalate during the chemical extraction process. In conclusion, the chemical route to Li extraction provides additional opportunities to investigate delithiation while avoiding the complications associated with electrolyte breakdown and simplifying in-situ measurements.
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Affiliation(s)
- E Salagre
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, Spain
| | - S Quílez
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, Spain
| | - R de Benito
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, Spain
| | - M Jaafar
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, Spain.,IFIMAC (Condensed Matter Physics Center), Universidad Autónoma de Madrid, Madrid, Spain
| | - H P van der Meulen
- Departamento de Física de Materiales, Universidad Autónoma de Madrid, Madrid, Spain.,Instituto Universitario de Ciencia de Materiales Nicolás Cabrera, Universidad Autónoma de Madrid, Madrid, Spain
| | - E Vasco
- Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - R Cid
- Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas, Madrid, Spain.,BM25-SpLine (Spanish CRG Beamline) at the European Synchrotron (E.S.R.F.), Grenoble, France.,Centre for Cooperative Research on Alternative Energies (CIC energiGUNE), Basque Research and Technology Alliance (BRTA), Vitoria-Gasteiz, Spain
| | - E J Fuller
- Sandia National Laboratories, Livermore, CA, USA
| | - A A Talin
- Sandia National Laboratories, Livermore, CA, USA
| | - P Segovia
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, Spain.,IFIMAC (Condensed Matter Physics Center), Universidad Autónoma de Madrid, Madrid, Spain.,Instituto Universitario de Ciencia de Materiales Nicolás Cabrera, Universidad Autónoma de Madrid, Madrid, Spain
| | - E G Michel
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, Spain.,IFIMAC (Condensed Matter Physics Center), Universidad Autónoma de Madrid, Madrid, Spain.,Instituto Universitario de Ciencia de Materiales Nicolás Cabrera, Universidad Autónoma de Madrid, Madrid, Spain
| | - C Polop
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, Spain. .,IFIMAC (Condensed Matter Physics Center), Universidad Autónoma de Madrid, Madrid, Spain. .,Instituto Universitario de Ciencia de Materiales Nicolás Cabrera, Universidad Autónoma de Madrid, Madrid, Spain.
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8
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Gibaja C, Rodríguez-San-Miguel D, Paz WS, Torres I, Salagre E, Segovia P, Michel EG, Assebban M, Ares P, Hernández-Maldonado D, Ramasse Q, Abellán G, Gómez-Herrero J, Varela M, Palacios JJ, Zamora F. Exfoliation of Alpha-Germanium: A Covalent Diamond-Like Structure. Adv Mater 2021; 33:e2006826. [PMID: 33543546 DOI: 10.1002/adma.202006826] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/20/2020] [Indexed: 05/28/2023]
Abstract
2D materials have opened a new field in materials science with outstanding scientific and technological impact. A largely explored route for the preparation of 2D materials is the exfoliation of layered crystals with weak forces between their layers. However, its application to covalent crystals remains elusive. Herein, a further step is taken by introducing the exfoliation of germanium, a narrow-bandgap semiconductor presenting a 3D diamond-like structure with strong covalent bonds. Pure α-germanium is exfoliated following a simple one-step procedure assisted by wet ball-milling, allowing gram-scale fabrication of high-quality layers with large lateral dimensions and nanometer thicknesses. The generated flakes are thoroughly characterized by different techniques, giving evidence that the new 2D material exhibits bandgaps that depend on both the crystallographic direction and the number of layers. Besides potential technological applications, this work is also of interest for the search of 2D materials with new properties.
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Affiliation(s)
- Carlos Gibaja
- Departamento de Química Inorgánica, Institute for Advanced Research in Chemical Sciences (IAdChem) and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, 28049, Spain
| | - David Rodríguez-San-Miguel
- Departamento de Química Inorgánica, Institute for Advanced Research in Chemical Sciences (IAdChem) and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, 28049, Spain
| | - Wendel S Paz
- Departamento de Física, Universidade Federal do Espírito Santo, Vitória, ES, 29075-910, Brazil
| | - Iñigo Torres
- Departamento de Química Inorgánica, Institute for Advanced Research in Chemical Sciences (IAdChem) and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, 28049, Spain
| | - Elena Salagre
- Departamento de Física de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, 28049, Spain
| | - Pilar Segovia
- Departamento de Física de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, 28049, Spain
| | - Enrique G Michel
- Departamento de Física de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, 28049, Spain
| | - Mhamed Assebban
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, Catedrático José Beltrán 2, Paterna, Valencia, 46980, Spain
- Department of Chemistry and Pharmacy & Joint Institute of Advanced Materials and Processes (ZMP), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Dr.-Mack-Straße 81, Fürth, 90762, Germany
| | - Pablo Ares
- Departamento de Física de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, 28049, Spain
- Department of Physics and Astronomy and National Graphene Institute, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - David Hernández-Maldonado
- Facultad de CC, Físicas & Instituto Pluridisciplinar, Universidad Complutense de Madrid, Madrid, 28040, Spain
- SuperSTEM, SciTech Daresbury Science and Innovation Campus, Block J. Keckwick Lane, Daresbury, WA4 4AD, UK
| | - Quentin Ramasse
- SuperSTEM, SciTech Daresbury Science and Innovation Campus, Block J. Keckwick Lane, Daresbury, WA4 4AD, UK
- School of Chemical and Process Engineering & School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK
| | - Gonzalo Abellán
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, Catedrático José Beltrán 2, Paterna, Valencia, 46980, Spain
- Department of Chemistry and Pharmacy & Joint Institute of Advanced Materials and Processes (ZMP), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Dr.-Mack-Straße 81, Fürth, 90762, Germany
| | - Julio Gómez-Herrero
- Departamento de Física de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, 28049, Spain
- Instituto Nicolás Cabrera (INC), Universidad Autónoma de Madrid, Madrid, 28049, Spain
| | - Maria Varela
- Facultad de CC, Físicas & Instituto Pluridisciplinar, Universidad Complutense de Madrid, Madrid, 28040, Spain
| | - Juan José Palacios
- Departamento de Física de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, 28049, Spain
- Instituto Nicolás Cabrera (INC), Universidad Autónoma de Madrid, Madrid, 28049, Spain
| | - Félix Zamora
- Departamento de Química Inorgánica, Institute for Advanced Research in Chemical Sciences (IAdChem) and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, 28049, Spain
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9
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García-Arroyo P, Navalpotro P, Mancheño MJ, Salagre E, Cabrera-Trujillo JJ, Michel EG, Segura JL, Carretero-González J. Acidic triggering of reversible electrochemical activity in a pyrenetetraone-based 2D polymer. POLYMER 2021. [DOI: 10.1016/j.polymer.2020.123273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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10
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Chen G, Mascaraque A, Jia H, Zimmermann B, Robertson M, Conte RL, Hoffmann M, González Barrio MA, Ding H, Wiesendanger R, Michel EG, Blügel S, Schmid AK, Liu K. Large Dzyaloshinskii-Moriya interaction induced by chemisorbed oxygen on a ferromagnet surface. Sci Adv 2020; 6:eaba4924. [PMID: 32851165 PMCID: PMC7428341 DOI: 10.1126/sciadv.aba4924] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 07/01/2020] [Indexed: 05/30/2023]
Abstract
The Dzyaloshinskii-Moriya interaction (DMI) is an antisymmetric exchange interaction that stabilizes chiral spin textures. It is induced by inversion symmetry breaking in noncentrosymmetric lattices or at interfaces. Recently, interfacial DMI has been found in magnetic layers adjacent to transition metals due to the spin-orbit coupling and at interfaces with graphene due to the Rashba effect. We report direct observation of strong DMI induced by chemisorption of oxygen on a ferromagnetic layer at room temperature. The sign of this DMI and its unexpectedly large magnitude-despite the low atomic number of oxygen-are derived by examining the oxygen coverage-dependent evolution of magnetic chirality. We find that DMI at the oxygen/ferromagnet interface is comparable to those at ferromagnet/transition metal interfaces; it has enabled direct tailoring of skyrmion's winding number at room temperature via oxygen chemisorption. This result extends the understanding of the DMI, opening up opportunities for the chemisorption-related design of spin-orbitronic devices.
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Affiliation(s)
- Gong Chen
- Physics Department, University of California, Davis, CA 95616, USA
| | - Arantzazu Mascaraque
- Depto. Física de Materiales, Universidad Complutense de Madrid, 28040 Madrid, Spain
- Unidad Asociada IQFR(CSIC)-UCM, Madrid E-28040, Spain
| | - Hongying Jia
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
| | - Bernd Zimmermann
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
| | | | - Roberto Lo Conte
- Department of Materials Science and Engineering, University of California, Berkeley, CA 94720, USA
- Department of Physics, University of Hamburg, D-20355 Hamburg, Germany
| | - Markus Hoffmann
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
| | | | - Haifeng Ding
- National Laboratory of Solid State Microstructures, Department of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, 22 Hankou Road, Nanjing 210093, People’s Republic of China
| | | | - Enrique G. Michel
- Depto. de Física de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Stefan Blügel
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
| | - Andreas K. Schmid
- NCEM, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Kai Liu
- Physics Department, University of California, Davis, CA 95616, USA
- Physics Department, Georgetown University, Washington, DC 20057, USA
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11
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Royuela S, Almarza J, Mancheño MJ, Pérez‐Flores JC, Michel EG, Ramos MM, Zamora F, Ocón P, Segura JL. Synergistic Effect of Covalent Bonding and Physical Encapsulation of Sulfur in the Pores of a Microporous COF to Improve Cycling Performance in Li‐S Batteries. Chemistry 2019; 25:12394-12404. [DOI: 10.1002/chem.201902052] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Indexed: 11/08/2022]
Affiliation(s)
- Sergio Royuela
- Departamento de Química Orgánica I, Facultad de CC. QuímicasUniversidad Complutense de Madrid Madrid 28040 Spain
- Departamento de Tecnología QuímicayAmbientalUniversidad Rey Juan Carlos Madrid 28933 Spain
| | - Joaquín Almarza
- Departamento de Química Orgánica I, Facultad de CC. QuímicasUniversidad Complutense de Madrid Madrid 28040 Spain
- Departamento de Química Física AplicadaFacultad de CienciasUniversidad Autónoma de Madrid Madrid 28049 Spain
| | - María J. Mancheño
- Departamento de Química Orgánica I, Facultad de CC. QuímicasUniversidad Complutense de Madrid Madrid 28040 Spain
| | - Juan C. Pérez‐Flores
- Instituto de Energías RenovablesUniversidad de Castilla-La Mancha Albacete 02006 Spain
| | - Enrique G. Michel
- Departamento de Física de la Materia CondensadaUniversidad Autónoma de Madrid Madrid 28049 Spain
- Condensed Matter Physics Center (IFIMAC)Universidad Autónoma de Madrid Madrid 28049 Spain
| | - María M. Ramos
- Departamento de Tecnología QuímicayAmbientalUniversidad Rey Juan Carlos Madrid 28933 Spain
| | - Félix Zamora
- Condensed Matter Physics Center (IFIMAC)Universidad Autónoma de Madrid Madrid 28049 Spain
- Departamento de Química InorgánicaFacultad de CienciasUniversidad Autónoma de Madrid Madrid 28049 Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem)Universidad Autónoma de Madrid Madrid 28049 Spain
- Instituto Madrileño de Estudios Avanzados en Nanociencia, (IMDEA-Nanociencia) Madrid 28049 Spain
| | - Pilar Ocón
- Departamento de Química Física AplicadaFacultad de CienciasUniversidad Autónoma de Madrid Madrid 28049 Spain
| | - José L. Segura
- Departamento de Química Orgánica I, Facultad de CC. QuímicasUniversidad Complutense de Madrid Madrid 28040 Spain
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12
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Martínez-Blanco J, Joco V, Quirós C, Segovia P, Michel EG. Crystalline Structure and Vacancy Ordering across a Surface Phase Transition in Sn/Cu(001). J Phys Chem B 2018; 122:745-756. [PMID: 28885023 DOI: 10.1021/acs.jpcb.7b06398] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report a surface X-ray diffraction study of the crystalline structure changes and critical behavior across the (3√2 × √2)R45° → (√2 × √2)R45° surface phase transition at 360 K for 0.5 monolayers of Sn on Cu(100). The phase transition is of the order-disorder type and is due to the disordering of the Cu atomic vacancies present in the low temperature phase. Two different atomic sites for Sn atoms, characterized by two different heights, are maintained across the surface phase transition.
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Affiliation(s)
- J Martínez-Blanco
- Departamento de Fı́sica de la Materia Condensada, Universidad Autónoma de Madrid , 28049, Madrid, Spain
| | - V Joco
- Departamento de Fı́sica de la Materia Condensada, Universidad Autónoma de Madrid , 28049, Madrid, Spain
| | - C Quirós
- Departamento de Fı́sica, Universidad de Oviedo , 33007 Oviedo, Spain.,Centro de Investigación en Nanomateriales y Nanotecnologı́a, CINN (CSIC - Universidad de Oviedo) , 33940 El Entrego, Spain
| | - P Segovia
- Departamento de Fı́sica de la Materia Condensada, Universidad Autónoma de Madrid , 28049, Madrid, Spain.,Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid , 28049 Madrid, Spain.,Instituto Universitario de Ciencia de Materiales "Nicolás Cabrera", Universidad Autónoma de Madrid , 28049 Madrid, Spain
| | - E G Michel
- Departamento de Fı́sica de la Materia Condensada, Universidad Autónoma de Madrid , 28049, Madrid, Spain.,Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid , 28049 Madrid, Spain.,Instituto Universitario de Ciencia de Materiales "Nicolás Cabrera", Universidad Autónoma de Madrid , 28049 Madrid, Spain
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13
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Abellán G, Ares P, Wild S, Nuin E, Neiss C, Miguel DR, Segovia P, Gibaja C, Michel EG, Görling A, Hauke F, Gómez‐Herrero J, Hirsch A, Zamora F. Noncovalent Functionalization and Charge Transfer in Antimonene. Angew Chem Int Ed Engl 2017; 56:14389-14394. [PMID: 28945952 PMCID: PMC5698728 DOI: 10.1002/anie.201702983] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 09/21/2017] [Indexed: 11/15/2022]
Abstract
Antimonene, a novel group 15 two-dimensional material, is functionalized with a tailormade perylene bisimide through strong van der Waals interactions. The functionalization process leads to a significant quenching of the perylene fluorescence, and surpasses that observed for either graphene or black phosphorus, thus allowing straightforward characterization of the flakes by scanning Raman microscopy. Furthermore, scanning photoelectron microscopy studies and theoretical calculations reveal a remarkable charge-transfer behavior, being twice that of black phosphorus. Moreover, the excellent stability under environmental conditions of pristine antimonene has been tackled, thus pointing towards the spontaneous formation of a sub-nanometric oxide passivation layer. DFT calculations revealed that the noncovalent functionalization of antimonene results in a charge-transfer band gap of 1.1 eV.
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Affiliation(s)
- Gonzalo Abellán
- Department of Chemistry and Pharmacy and Joint Institute of Advanced Materials and Processes (ZMP)University Erlangen-NürnbergHenkestr. 4291054ErlangenGermany
- Dr.-Mack Str. 8190762FürthGermany
| | - Pablo Ares
- Departamento de Física de la Materia CondensadaUniversidad Autónoma de MadridMadridE-28049Spain
| | - Stefan Wild
- Department of Chemistry and Pharmacy and Joint Institute of Advanced Materials and Processes (ZMP)University Erlangen-NürnbergHenkestr. 4291054ErlangenGermany
- Dr.-Mack Str. 8190762FürthGermany
| | - Edurne Nuin
- Department of Chemistry and Pharmacy and Joint Institute of Advanced Materials and Processes (ZMP)University Erlangen-NürnbergHenkestr. 4291054ErlangenGermany
- Dr.-Mack Str. 8190762FürthGermany
| | - Christian Neiss
- Theoretical ChemistryUniversity Erlangen-NürnbergEgerlandstr. 391058ErlangenGermany
| | - David Rodriguez‐San Miguel
- Departamento de Química Inorgánica, Institute for Advanced Research in Chemical Sciences (IAdChem)Universidad Autónoma de Madrid28049MadridSpain
| | - Pilar Segovia
- Departamento de Física de la Materia CondensadaUniversidad Autónoma de MadridMadridE-28049Spain
- Condensed Matter Physics Center (IFIMAC)Universidad Autónoma de MadridMadridE-28049Spain
| | - Carlos Gibaja
- Departamento de Química Inorgánica, Institute for Advanced Research in Chemical Sciences (IAdChem)Universidad Autónoma de Madrid28049MadridSpain
| | - Enrique G. Michel
- Departamento de Física de la Materia CondensadaUniversidad Autónoma de MadridMadridE-28049Spain
- Condensed Matter Physics Center (IFIMAC)Universidad Autónoma de MadridMadridE-28049Spain
| | - Andreas Görling
- Theoretical ChemistryUniversity Erlangen-NürnbergEgerlandstr. 391058ErlangenGermany
| | - Frank Hauke
- Department of Chemistry and Pharmacy and Joint Institute of Advanced Materials and Processes (ZMP)University Erlangen-NürnbergHenkestr. 4291054ErlangenGermany
- Dr.-Mack Str. 8190762FürthGermany
| | - Julio Gómez‐Herrero
- Departamento de Física de la Materia CondensadaUniversidad Autónoma de MadridMadridE-28049Spain
- Condensed Matter Physics Center (IFIMAC)Universidad Autónoma de MadridMadridE-28049Spain
| | - Andreas Hirsch
- Department of Chemistry and Pharmacy and Joint Institute of Advanced Materials and Processes (ZMP)University Erlangen-NürnbergHenkestr. 4291054ErlangenGermany
- Dr.-Mack Str. 8190762FürthGermany
| | - Félix Zamora
- Departamento de Química Inorgánica, Institute for Advanced Research in Chemical Sciences (IAdChem)Universidad Autónoma de Madrid28049MadridSpain
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia), Cantoblanco28049MadridSpain
- Condensed Matter Physics Center (IFIMAC)Universidad Autónoma de MadridMadridE-28049Spain
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14
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Tejeda A, Michel EG, Mascaraque A. The dimensionality reduction at surfaces as a playground for many-body and correlation effects. J Phys Condens Matter 2013; 25:090301. [PMID: 23530266 DOI: 10.1088/0953-8984/25/9/090301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
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15
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Michel EG. Perspectives on surface science. J Phys Condens Matter 2010; 22:080302. [PMID: 21422509 DOI: 10.1088/0953-8984/22/8/080302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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16
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Joco V, Martínez-Blanco J, Segovia P, Vobornik I, Michel EG. Surface electronic structure of Pb/Cu(100): surface band filling and folding. J Phys Condens Matter 2009; 21:474216. [PMID: 21832495 DOI: 10.1088/0953-8984/21/47/474216] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report an investigation into the surface electronic structure of Pb/Cu(100) in the submonolayer coverage range. A prominent surface band is detected in the whole coverage range analysed. The band is gradually filled as Pb coverage increases. For a Pb coverage of 0.375 ML, corresponding to the c(4 × 4) phase, a strong c(4 × 4) folding of this state is observed in the valence band. The origin of these results and the nature of the surface electronic structure of Pb/Cu(100)- c(4 × 4) are discussed.
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Affiliation(s)
- V Joco
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain
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17
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Abstract
Abstract
The adsorption systems Pb/Ge(111) and Sn/Ge(111) exhibit temperature induced structural phase transitions. We report here a phenomenological analysis of these phase transitions starting from Landau theory. On the basis of symmetry arguments, we show that essential differences are expected theoretically for the critical behav ior of the two interfaces. The influence of hopping defects in these systems is treated using a Landau-like approach. This approach gives us a consistent and general manner to interpret the existing experimental data for these interfaces.
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18
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Martínez-Blanco J, Joco V, Quirós C, Segovia P, Michel EG. Surface x-ray diffraction analysis using a genetic algorithm: the case of Sn/Cu(100)-[Formula: see text]. J Phys Condens Matter 2009; 21:134011. [PMID: 21817486 DOI: 10.1088/0953-8984/21/13/134011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The application of genetic algorithms to the analysis of surface x-ray diffraction data is discussed and the implementation of a genetic algorithm of evolutionary type is described in detail. The structure of Sn/Cu(100)-[Formula: see text] is determined on the basis of surface x-ray diffraction data analysed using this algorithm. The results are compared to previous findings using other techniques.
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Affiliation(s)
- J Martínez-Blanco
- Departamento de Física de la Materia Condensada and Instituto Universitario de Ciencia de Materiales 'Nicolás Cabrera', Universidad Autónoma de Madrid, E-28049 Madrid, Spain
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Abstract
We present measurements of the Fermi surface and underlying band structure of Sn/Cu(100)-[Formula: see text]. This phase is observed for a coverage of 0.60-0.65 monolayers. Its electronic structure is characterized by a free-electron-like surface band folded with the reconstruction periodicity. At variance with other surface phases of Sn on Cu(100), no temperature-induced phase transition is observed for this phase from 100 K up to the desorption of Sn.
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Affiliation(s)
- J Martínez-Blanco
- Departamento de Física de la Materia Condensada and Instituto Universitario de Ciencia de Materiales 'Nicolás Cabrera', Universidad Autónoma de Madrid, E-28049 Madrid, Spain
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20
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Tejeda A, Cortés R, Lobo-Checa J, Didiot C, Kierren B, Malterre D, Michel EG, Mascaraque A. Structural origin of the Sn 4d core level line shape in Sn/Ge(111)-(3x3). Phys Rev Lett 2008; 100:026103. [PMID: 18232889 DOI: 10.1103/physrevlett.100.026103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Indexed: 05/25/2023]
Abstract
High-resolution photoemission of the Sn 4d core level of Sn/Ge(111)-(3x3) resolves three main components in the line shape, which are assigned to each of the three Sn atoms that form the unit cell. The line shape found is in agreement with an initial state picture and supports that the two down atoms are inequivalent. In full agreement with these results, scanning tunnel microscopy images directly show that the two down atoms are at slightly different heights in most of the surface, giving rise to an inequivalent-down-atoms (3x3) structure. These results solve a long-standing controversy on the interpretation of the Sn 4d core-level line shape and the structure of Sn/Ge(111)-(3x3).
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Affiliation(s)
- A Tejeda
- Matériaux et Phénomènes Quantiques, CNRS, Université Paris Diderot, 75205 Paris, France
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21
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Cortés R, Tejeda A, Lobo J, Didiot C, Kierren B, Malterre D, Michel EG, Mascaraque A. Observation of a Mott insulating ground state for Sn/Ge(111) at low temperature. Phys Rev Lett 2006; 96:126103. [PMID: 16605931 DOI: 10.1103/physrevlett.96.126103] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2005] [Indexed: 05/08/2023]
Abstract
We report an investigation on the properties of 0.33 ML of Sn on Ge(111) at temperatures down to 5 K. Low-energy electron diffraction and scanning tunneling microscopy show that the (3x3) phase formed at approximately 200 K, reverts to a new ((square root 3)x(square root 3))R30 degrees phase below 30 K. The vertical distortion characteristic of the (3x3) phase is lost across the phase transition, which is fully reversible. Angle-resolved photoemission experiments show that, concomitantly with the structural phase transition, a metal-insulator phase transition takes place. The ((square root 3)x(square root 3))R30 degrees ground state is interpreted as the formation of a Mott insulator for a narrow half-filled band in a two-dimensional triangular lattice.
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Affiliation(s)
- R Cortés
- Departamento de Física de Materiales, Universidad Complutense de Madrid, 28040 Madrid, Spain
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22
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Cano A, Levanyuk AP, Michel EG. [Formula: see text] ↔ (3 × 3) phase transition in Pb/Ge(111) and Sn/Ge(111): a phenomenological study on the phase transition anomalies and the role of defects. Nanotechnology 2005; 16:325-333. [PMID: 21727444 DOI: 10.1088/0957-4484/16/2/026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A phenomenological study of the [Formula: see text] phase transitions occurring in the adsorption systems Pb/Ge(111) and Sn/Ge(111) is presented. The starting point of such a study is the Landau theory. The critical behaviour expected theoretically for the two interfaces, and the corresponding influence of defects, are discussed in detail. Symmetry arguments show that, contrary to general belief, the critical behaviours of Pb/Ge(111) and Sn/Ge(111) are essentially different. The Landau-like approach employed to study the influence of defects provides a consistent and general manner to interpret the existing experimental data. Special attention is paid to the influence of hopping defects in Sn/Ge(111).
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Affiliation(s)
- A Cano
- Departamento de Física de la Materia Condensada C-III, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
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23
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Lobo J, Michel EG, Bachmann AR, Speller S, Kuntze J, Ortega JE. Tuning the surface state dimensionality of Cu nanostripes. Phys Rev Lett 2004; 93:137602. [PMID: 15524761 DOI: 10.1103/physrevlett.93.137602] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2004] [Indexed: 05/24/2023]
Abstract
Stepped Cu nanostripes with varying terrace widths are self-assembled during Ag-induced periodic faceting of vicinal Cu(111). By changing Ag coverage the average terrace size within individual Cu stripes is readily tuned, making it possible to select the one-dimensional or two-dimensional character of surface states. Furthermore, the average terrace size can be smoothly switched from 10 to 30 A, thereby tracking the transition from step-lattice, quasi-two-dimensional umklapp bands to terrace-confined one-dimensional quantum well states.
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Affiliation(s)
- J Lobo
- Departamento de Física de la Materia Condensada and Instituto Universitario de Ciencia de Materiales Nicolás Cabrera, Universidad Autónoma de Madrid, 28049 Madrid, Spain
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Farías D, Kamiński W, Lobo J, Ortega J, Hulpke E, Pérez R, Flores F, Michel EG. Phonon softening, chaotic motion, and order-disorder transition in Sn/Ge(111). Phys Rev Lett 2003; 91:016103. [PMID: 12906557 DOI: 10.1103/physrevlett.91.016103] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2003] [Indexed: 05/24/2023]
Abstract
The phonon dynamics of the Sn/Ge(111) interface is studied using high-resolution helium atom scattering and first-principles calculations. At room temperature we observe a phonon softening at the Kmacr; point in the (sqrt[3]xsqrt[3])R30 degrees phase, associated with the stabilization of a (3x3) phase at low temperature. That phonon band is split into three branches in the (3x3) phase. We analyze the character of these phonons and find out that the low- and room-temperature modes are connected via a chaotic motion of the Sn atoms. The system is shown to present an order-disorder transition.
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Affiliation(s)
- D Farías
- Departamento de Física de la Materia Condensada and Instituto Nicolás Cabrera, Universidad Autónoma, 28049 Madrid, Spain
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Ortega JE, Speller S, Bachmann AR, Mascaraque A, Michel EG, Närmann A, Mugarza A, Rubio A, Himpsel FJ. Electron wave function at a vicinal surface: switch from terrace to step modulation. Phys Rev Lett 2000; 84:6110-6113. [PMID: 10991136 DOI: 10.1103/physrevlett.84.6110] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/1999] [Indexed: 05/23/2023]
Abstract
The Cu(111) surface state has been mapped for vicinal surfaces with variable step densities by angle-resolved photoemission. Using tunable synchrotron radiation to vary the k dependence perpendicular to the surface, as well as the (k) dependence, we find a switch between two qualitatively different regimes at a miscut of 7 degrees (17 A terrace width). For larger miscut angles the step modulation of the wave function dominates, and for smaller miscut angles the terrace modulation dominates. These observations resolve an apparent inconsistency between prior photoemission and STM results.
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Affiliation(s)
- J E Ortega
- Centro Mixto CSIC-UPV and Donostia International Physics Center, Departamento de Física Aplicada I, Universidad del País Vasco, Plaza Oñate 2, 20018-San Sebastián, Spain
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Segovia P, Castro GR, Mascaraque A, Prieto P, Kim HJ, Michel EG. Origin of the surface metallization in single-domain K/Si(100)2 x 1. Phys Rev B Condens Matter 1996; 54:R14277-R14280. [PMID: 9985506 DOI: 10.1103/physrevb.54.r14277] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Segovia P, Michel EG, Ortega JE. Quantum Well States and Short Period Oscillations of the Density of States at the Fermi Level in Cu Films Grown on fcc Co(100). Phys Rev Lett 1996; 77:3455-3458. [PMID: 10062224 DOI: 10.1103/physrevlett.77.3455] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Eteläniemi V, Michel EG, Materlik G. X-ray standing-wave study of alkali-metal/Si(111)7 x 7 interfaces. Phys Rev B Condens Matter 1993; 48:12023-12031. [PMID: 10007549 DOI: 10.1103/physrevb.48.12023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Alvarez J, Hinarejos JJ, Michel EG, Ocal C, Miranda R. Initial stages of the growth of Fe on Si(111)7 x 7. Phys Rev B Condens Matter 1993; 47:16048-16051. [PMID: 10006023 DOI: 10.1103/physrevb.47.16048] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Alvarez J, Hinarejos JJ, Michel EG, Castro GR, Miranda R. Electronic structure of iron silicides grown on Si(100) determined by photoelectron spectroscopies. Phys Rev B Condens Matter 1992; 45:14042-14051. [PMID: 10001522 DOI: 10.1103/physrevb.45.14042] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Michel EG, Pervan P, Castro GR, Miranda R, Wandelt K. Structural and electronic properties of K/Si(100)2 x 1. Phys Rev B Condens Matter 1992; 45:11811-11822. [PMID: 10001196 DOI: 10.1103/physrevb.45.11811] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Michel EG, Ortega JE, Oellig EM, Asensio MC, Ferrón J, Miranda R. Early stages of the alkali-metal-promoted oxidation of silicon. Phys Rev B Condens Matter 1988; 38:13399-13406. [PMID: 9946322 DOI: 10.1103/physrevb.38.13399] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Michel EG, Alvarez J, Asensio MC, Miranda R, Ibáez J, Peral G, Vicent JL, García F, Morán E, Alario-Franco MA. Photoemission study of a high-Tc superconducting Bi-Sr-Ca-Cu oxide. Phys Rev B Condens Matter 1988; 38:5146-5149. [PMID: 9946941 DOI: 10.1103/physrevb.38.5146] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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