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Albani G, Capra M, Lodesani A, Calloni A, Bussetti G, Finazzi M, Ciccacci F, Brambilla A, Duò L, Picone A. Self-assembly of C 60 on a ZnTPP/Fe(001)- p(1 × 1)O substrate: observation of a quasi-freestanding C 60 monolayer. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2022; 13:857-864. [PMID: 36105692 PMCID: PMC9443418 DOI: 10.3762/bjnano.13.76] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 08/11/2022] [Indexed: 06/15/2023]
Abstract
Fullerene (C60) has been deposited in ultrahigh vacuum on top of a zinc tetraphenylporphyrin (ZnTPP) monolayer self-assembled on a Fe(001)-p(1 × 1)O substrate. The nanoscale morphology and the electronic properties of the C60/ZnTPP/Fe(001)-p(1 × 1)O heterostructure have been investigated by scanning tunneling microscopy/spectroscopy and ultraviolet photoemission spectroscopy. C60 nucleates compact and well-ordered hexagonal domains on top of the ZnTPP buffer layer, suggesting a high surface diffusivity of C60 and a weak coupling between the overlayer and the substrate. Accordingly, work function measurements reveal a negligible charge transfer at the C60/ZnTPP interface. Finally, the difference between the energy of the lowest unoccupied molecular orbital (LUMO) and that of the highest occupied molecular orbital (HOMO) measured on C60 is about 3.75 eV, a value remarkably higher than those found in fullerene films stabilized directly on metal surfaces. Our results unveil a model system that could be useful in applications in which a quasi-freestanding monolayer of C60 interfaced with a metallic electrode is required.
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Affiliation(s)
- Guglielmo Albani
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Michele Capra
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Alessandro Lodesani
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Alberto Calloni
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Gianlorenzo Bussetti
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Marco Finazzi
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Franco Ciccacci
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Alberto Brambilla
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Lamberto Duò
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Andrea Picone
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
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Picone A, Finazzi M, Duò L, Giannotti D, Ciccacci F, Brambilla A. Observation of a Metastable Honeycomb Arrangement of C 60 on Ni(111) with (7 × 7) Periodicity: Tailoring an Interface for Organic Spintronics. ACS APPLIED NANO MATERIALS 2021; 4:12993-13000. [PMID: 34977478 PMCID: PMC8713361 DOI: 10.1021/acsanm.1c02060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 11/23/2021] [Indexed: 06/14/2023]
Abstract
Hybrid nanostructures in which organic molecules are interfaced with metal surfaces hold promise for the discovery of intriguing physical and chemical phenomena, as well as for the development of innovative devices. In this frame, it is crucial to understand the interplay between the structural details of the interface and the electronic properties of the system. Here, an experimental investigation of the C60/Ni(111) interface is performed by means of scanning tunneling microscopy/spectroscopy (STM/STS) and low-energy electron diffraction (LEED). The deposition of C60 at room temperature, followed by high-temperature annealing, promotes the stabilization of two different phases. A hitherto unreported phase forming a (7 × 7) honeycomb overlayer coexists with the well-known (4 × 4) reconstruction. Highly resolved STM images disclose the adsorption geometry of the molecules for both phases. STS reveals that the electronic properties of C60/Ni(111) are strongly influenced by the morphology of the interface, suggesting the possibility of tuning the electronic properties of the organic/inorganic heterostructures by adjusting the structural coupling with the substrate. This achievement can be important for hybrid magnetic interfaces, where the harmonization between the molecular and the magnetic orders can enhance the development of hybrid magnetic states.
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Janke W, Speck T. Multiscale modeling of structure formation of C 60 on insulating CaF 2 substrates. J Chem Phys 2021; 154:234701. [PMID: 34241269 DOI: 10.1063/5.0051188] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Morphologies of adsorbed molecular films are of interest in a wide range of applications. To study the epitaxial growth of these systems in computer simulations requires access to long time and length scales, and one typically resorts to kinetic Monte Carlo (KMC) simulations. However, KMC simulations require as input transition rates and their dependence on external parameters (such as temperature). Experimental data allow only limited and indirect access to these rates, and models are often oversimplified. Here, we follow a bottom-up approach and aim at systematically constructing all relevant rates for an example system that has shown interesting properties in experiments, buckminsterfullerene on a calcium fluoride substrate. We develop classical force fields (both atomistic and coarse-grained) and perform molecular dynamics simulations of the elementary transitions in order to derive explicit expressions for the transition rates with a minimal number of free parameters.
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Affiliation(s)
- William Janke
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7-9, 55128 Mainz, Germany
| | - Thomas Speck
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7-9, 55128 Mainz, Germany
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Hsu CC, Hsu KL, Chang PC, Liu SY, Hsu CC, Lin WC. Organic/metal interface-modulated magnetism in [Fe/C 60] 3 multilayers and Fe-C 60 composites. NANOTECHNOLOGY 2020; 31:325701. [PMID: 32311680 DOI: 10.1088/1361-6528/ab8b0a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Because of the expected long spin-transport length of organic materials, the magnetic metal/organic interface is crucial to the application of organic spintronics. In this study, [Fe/C60]3 multilayers were fabricated for the investigation of C60-mediated magnetic interlayer coupling. [Fe/C60]3 thin films were characterized using the magneto-optical Kerr effect, transmission electron microscopy, Raman spectroscopy, and x-ray photoelectron spectroscopy (XPS). The thin films revealed in-plane magnetic anisotropy, and the magnetic coercivity (H c ) drastically decreased from 6-8 mT to 0.5 mT with the increase of C60 thickness from 0.1 nm to 5 nm. The insertion of the C60 layer considerably reduced H c because a thickness greater than 1 nm of the C60 layer is sufficient for blocking magnetic exchange coupling between Fe layers. In addition, post-annealing increased H c because of Fe inter-diffusion, which promotes magnetic exchange coupling and further Fe-C bonding, as confirmed by a comparative study of XPS C-spectra. The thermally triggered inter-diffusion between Fe and C60 layers turned the multilayers into a mixed composite film and thus caused magnetic variation. Annealing time and temperature can be used as control parameters for the tuning of magnetism in Fe-C60 composites.
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Affiliation(s)
- Chuan-Che Hsu
- Department of Physics, National Taiwan Normal University, Taipei 11677, Taiwan
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Wu Y, Fan H, Yang C, Zhang L. Pyrene-based amphiphile regulated C60 aggregation in monolayers and Langmuir–Blodgett films. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2019.124111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Huang N, Wang K, Drake H, Cai P, Pang J, Li J, Che S, Huang L, Wang Q, Zhou HC. Tailor-Made Pyrazolide-Based Metal-Organic Frameworks for Selective Catalysis. J Am Chem Soc 2018; 140:6383-6390. [PMID: 29719956 DOI: 10.1021/jacs.8b02710] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The predesignable porous structures in metal-organic frameworks (MOFs) render them quite attractive as a host-guest platform to address a variety of important issues at the frontiers of science. In this work, a perfluorophenylene functionalized metalloporphyrinic MOF, namely, PCN-624, has been rationally designed, synthesized, and structurally characterized. PCN-624 is constructed by 12-connected [Ni8(OH)4(H2O)2Pz12] (Pz = pyrazolide) nodes and fluorinated 5,10,15,20-tetrakis(2,3,5,6-tetrafluoro-4-(1 H-pyrazol-4-yl)phenyl)-porphyrin (TTFPPP) linker with an ftw-a topological net. Notably, PCN-624 exhibits extinguished robustness under different conditions, including organic solvents, strong acid, and base aqueous solutions. The pore surface of PCN-624 is decorated with pendant perfluorophenylene groups. These moieties fabricate densely fluorinated nanocages resulting in the selective guest capture of the material. More importantly, PCN-624 can be employed as an efficient heterogeneous catalyst for the selective synthesis of fullerene-anthracene bisadduct. Owing to the high chemical robustness of PCN-624, it can be recycled over five times without significant loss of its catalytic activity. All of these results demonstrate that MOFs can serve as a powerful platform with great flexibility for functional design to solve various synthetic problems.
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Affiliation(s)
- Ning Huang
- Department of Chemistry , Texas A&M University , College Station , Texas 77842-3012 , United States
| | - Kecheng Wang
- Department of Chemistry , Texas A&M University , College Station , Texas 77842-3012 , United States
| | - Hannah Drake
- Department of Chemistry , Texas A&M University , College Station , Texas 77842-3012 , United States
| | - Peiyu Cai
- Department of Chemistry , Texas A&M University , College Station , Texas 77842-3012 , United States
| | - Jiandong Pang
- Department of Chemistry , Texas A&M University , College Station , Texas 77842-3012 , United States
| | - Jialuo Li
- Department of Chemistry , Texas A&M University , College Station , Texas 77842-3012 , United States
| | - Sai Che
- Department of Chemistry , Texas A&M University , College Station , Texas 77842-3012 , United States
| | - Lan Huang
- Department of Materials Science and Engineering , Texas A&M University , College Station , Texas 77843-3003 , United States
| | - Qi Wang
- Department of Chemistry , Texas A&M University , College Station , Texas 77842-3012 , United States
| | - Hong-Cai Zhou
- Department of Chemistry , Texas A&M University , College Station , Texas 77842-3012 , United States
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Shao Y, Pang R, Pan H, Shi X. Fullerene/layered antiferromagnetic reconstructed spinterface: Subsurface layer dominates molecular orbitals' spin-split and large induced magnetic moment. J Chem Phys 2018; 148:114704. [PMID: 29566528 DOI: 10.1063/1.5012926] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The interfaces between organic molecules and magnetic metals have gained increasing interest for both fundamental reasons and applications. Among them, the C60/layered antiferromagnetic (AFM) interfaces have been studied only for C60 bonded to the outermost ferromagnetic layer [S. L. Kawahara et al., Nano Lett. 12, 4558 (2012) and D. Li et al., Phys. Rev. B 93, 085425 (2016)]. Here, via density functional theory calculations combined with evidence from the literature, we demonstrate that C60 adsorption can reconstruct the layered-AFM Cr(001) surface at elevated annealing temperatures so that C60 bonds to both the outermost and the subsurface Cr layers in opposite spin directions. Surface reconstruction drastically changes the adsorbed molecule spintronic properties: (1) the spin-split p-d hybridization involves multi-orbitals of C60 and top two layers of Cr with opposite spin-polarization, (2) the subsurface Cr atom dominates the C60 electronic properties, and (3) the reconstruction induces a large magnetic moment of 0.58 μB in C60 as a synergistic effect of the top two Cr layers. The induced magnetic moment in C60 can be explained by the magnetic direct-exchange mechanism, which can be generalized to other C60/magnetic metal systems. Understanding these complex hybridization behaviors is a crucial step for molecular spintronic applications.
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Affiliation(s)
- Yangfan Shao
- Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Rui Pang
- International Laboratory of Quantum Functional Materials of Henan and School of Physics and Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Hui Pan
- Institute of Applied Physics and Materials Engineering, University of Macau, Macau, China
| | - Xingqiang Shi
- Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
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Brambilla A, Picone A, Giannotti D, Calloni A, Berti G, Bussetti G, Achilli S, Fratesi G, Trioni MI, Vinai G, Torelli P, Panaccione G, Duò L, Finazzi M, Ciccacci F. Enhanced Magnetic Hybridization of a Spinterface through Insertion of a Two-Dimensional Magnetic Oxide Layer. NANO LETTERS 2017; 17:7440-7446. [PMID: 29149565 DOI: 10.1021/acs.nanolett.7b03314] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Interfaces between organic semiconductors and ferromagnetic metals offer intriguing opportunities in the rapidly developing field of organic spintronics. Understanding and controlling the spin-polarized electronic states at the interface is the key toward a reliable exploitation of this kind of systems. Here we propose an approach consisting in the insertion of a two-dimensional magnetic oxide layer at the interface with the aim of both increasing the reproducibility of the interface preparation and offering a way for a further fine control over the electronic and magnetic properties. We have inserted a two-dimensional Cr4O5 layer at the C60/Fe(001) interface and have characterized the corresponding morphological, electronic, and magnetic properties. Scanning tunneling microscopy and electron diffraction show that the film grows well-ordered both in the monolayer and multilayer regimes. Electron spectroscopies confirm that hybridization of the electronic states occurs at the interface. Finally, magnetic dichroism in X-ray absorption shows an unprecedented spin-polarization of the hybridized fullerene states. The latter result is discussed also in light of an ab initio theoretical analysis.
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Affiliation(s)
- Alberto Brambilla
- Dipartimento di Fisica, Politecnico di Milano , piazza Leonardo da Vinci, 32, 20133 Milano, Italy
| | - Andrea Picone
- Dipartimento di Fisica, Politecnico di Milano , piazza Leonardo da Vinci, 32, 20133 Milano, Italy
| | - Dario Giannotti
- Dipartimento di Fisica, Politecnico di Milano , piazza Leonardo da Vinci, 32, 20133 Milano, Italy
| | - Alberto Calloni
- Dipartimento di Fisica, Politecnico di Milano , piazza Leonardo da Vinci, 32, 20133 Milano, Italy
| | - Giulia Berti
- Dipartimento di Fisica, Politecnico di Milano , piazza Leonardo da Vinci, 32, 20133 Milano, Italy
| | - Gianlorenzo Bussetti
- Dipartimento di Fisica, Politecnico di Milano , piazza Leonardo da Vinci, 32, 20133 Milano, Italy
| | - Simona Achilli
- Dipartimento di Fisica, Università degli Studi di Milano , Via Celoria, 16, 20133 Milano, Italy
| | - Guido Fratesi
- Dipartimento di Fisica, Università degli Studi di Milano , Via Celoria, 16, 20133 Milano, Italy
| | - Mario I Trioni
- CNR - National Research Council of Italy, ISTM , via Golgi 19, 20133 Milano, Italy
| | - Giovanni Vinai
- Laboratorio TASC, IOM-CNR , S.S. 14 km 163.5, Basovizza, I, 34149 Trieste, Italy
| | - Piero Torelli
- Laboratorio TASC, IOM-CNR , S.S. 14 km 163.5, Basovizza, I, 34149 Trieste, Italy
| | - Giancarlo Panaccione
- Laboratorio TASC, IOM-CNR , S.S. 14 km 163.5, Basovizza, I, 34149 Trieste, Italy
| | - Lamberto Duò
- Dipartimento di Fisica, Politecnico di Milano , piazza Leonardo da Vinci, 32, 20133 Milano, Italy
| | - Marco Finazzi
- Dipartimento di Fisica, Politecnico di Milano , piazza Leonardo da Vinci, 32, 20133 Milano, Italy
| | - Franco Ciccacci
- Dipartimento di Fisica, Politecnico di Milano , piazza Leonardo da Vinci, 32, 20133 Milano, Italy
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9
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Cinchetti M, Dediu VA, Hueso LE. Activating the molecular spinterface. NATURE MATERIALS 2017; 16:507-515. [PMID: 28439116 DOI: 10.1038/nmat4902] [Citation(s) in RCA: 140] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 03/23/2017] [Indexed: 05/19/2023]
Abstract
The miniaturization trend in the semiconductor industry has led to the understanding that interfacial properties are crucial for device behaviour. Spintronics has not been alien to this trend, and phenomena such as preferential spin tunnelling, the spin-to-charge conversion due to the Rashba-Edelstein effect and the spin-momentum locking at the surface of topological insulators have arisen mainly from emergent interfacial properties, rather than the bulk of the constituent materials. In this Perspective we explore inorganic/molecular interfaces by looking closely at both sides of the interface. We describe recent developments and discuss the interface as an ideal platform for creating new spin effects. Finally, we outline possible technologies that can be generated thanks to the unique active tunability of molecular spinterfaces.
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Affiliation(s)
- Mirko Cinchetti
- Experimentelle Physik VI, Technische Universität Dortmund, 44221 Dortmund, Germany
| | - V Alek Dediu
- Istituto per lo Studio dei Materiali Nanostrutturati CNRISMN, 40129 Bologna, Italy
| | - Luis E Hueso
- CIC nanoGUNE, 20018 San Sebastian, Spain
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
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