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Men E, Li D, Zhang H, Chen J, Qiao Z, Wei L, Wang Z, Xi C, Song D, Li Y, Jeen H, Chen K, Zhu H, Hao L. An atomically controlled insulator-to-metal transition in iridate/manganite heterostructures. Nat Commun 2024; 15:8427. [PMID: 39341802 PMCID: PMC11439077 DOI: 10.1038/s41467-024-52616-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 09/12/2024] [Indexed: 10/01/2024] Open
Abstract
All-insulator heterostructures with an emerging metallicity are at the forefront of material science, which typically contain at least one band insulator while it is not necessary to be. Here we show emergent phenomena in a series of all-correlated-insulator heterostructures that composed of insulating CaIrO3 and insulating La0.67Sr0.33MnO3. We observed an intriguing insulator-to-metal transition, that depends delicately on the thickness of the iridate component. The simultaneous enhancements of magnetization, electric conductivity, and magnetoresistance effect indicate a percolation-type nature of the insulator-to-metal transition, with the percolation threshold can be reached at an exceptionally low volume fraction of the iridate. Such a drastic transition is induced by an interfacial charge transfer, which interestingly alters the electronic and crystalline structures of the bulk region rather than the limited ultrathin interface. We further showcased the central role of effective correlation in modulating the insulator-to-metal transition, by demonstrating that the critical thickness of iridate for triggering the metallic state can be systematically reduced down to a single unit-cell layer.
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Affiliation(s)
- Enyang Men
- Anhui Key Laboratory of Low-Energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui, China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, China
| | - Deyang Li
- Anhui Key Laboratory of Low-Energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui, China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, China
| | - Haiyang Zhang
- Anhui Key Laboratory of Low-Energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui, China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, China
| | - Jingxin Chen
- Anhui Key Laboratory of Low-Energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui, China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, China
| | - Zhihan Qiao
- Anhui Key Laboratory of Low-Energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui, China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, China
| | - Long Wei
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China
| | - Zhaosheng Wang
- Anhui Key Laboratory of Low-Energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui, China
| | - Chuanying Xi
- Anhui Key Laboratory of Low-Energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui, China
| | - Dongsheng Song
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei, China
| | - Yuhan Li
- Department of Physics, Beijing Normal University, Beijing, China
| | - Hyoungjeen Jeen
- Department of Physics, Pusan National University, Busan, South Korea
| | - Kai Chen
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China.
| | - Hong Zhu
- Department of Physics, University of Science and Technology of China, Hefei, China.
| | - Lin Hao
- Anhui Key Laboratory of Low-Energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, Anhui, China.
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2
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Franceschi G, Heller R, Schmid M, Diebold U, Riva M. Evolution of the surface atomic structure of multielement oxide films: curse or blessing? NANOSCALE ADVANCES 2023; 5:7009-7017. [PMID: 38059015 PMCID: PMC10696924 DOI: 10.1039/d3na00847a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 11/02/2023] [Indexed: 12/08/2023]
Abstract
Atomically resolved scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS) are used to gain atomic-scale insights into the heteroepitaxy of lanthanum-strontium manganite (LSMO, La1-xSrxMnO3-δ, x ≈ 0.2) on SrTiO3(110). LSMO is a perovskite oxide characterized by several composition-dependent surface reconstructions. The flexibility of the surface allows it to incorporate nonstoichiometries during growth, which causes the structure of the surface to evolve accordingly. This happens up to a critical point, where phase separation occurs, clusters rich in the excess cations form at the surface, and films show a rough morphology. To limit the nonstoichiometry introduced by non-optimal growth conditions, it proves useful to monitor the changes in surface atomic structures as a function of the PLD parameters and tune the latter accordingly.
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Affiliation(s)
- Giada Franceschi
- Institute of Applied Physics, TU Wien Wiedner Hauptstraβe 8-10/E134 1040 Vienna Austria
| | - Renè Heller
- Institute of Ion Beam Physics and Materials Research Helmholtz-Zentrum Dresden-Rossendorf e.V., Bautzner Landstraße 400 01328 Dresden Germany
| | - Michael Schmid
- Institute of Applied Physics, TU Wien Wiedner Hauptstraβe 8-10/E134 1040 Vienna Austria
| | - Ulrike Diebold
- Institute of Applied Physics, TU Wien Wiedner Hauptstraβe 8-10/E134 1040 Vienna Austria
| | - Michele Riva
- Institute of Applied Physics, TU Wien Wiedner Hauptstraβe 8-10/E134 1040 Vienna Austria
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Machado P, Guzmán R, Morera RJ, Alcalà J, Palau A, Zhou W, Coll M. Chemical Synthesis of La 0.75Sr 0.25CrO 3 Thin Films for p-Type Transparent Conducting Electrodes. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2023; 35:3513-3521. [PMID: 37181670 PMCID: PMC10173867 DOI: 10.1021/acs.chemmater.2c03831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 03/24/2023] [Indexed: 05/16/2023]
Abstract
The imperative need for highly performant and stable p-type transparent electrodes based on abundant metals is stimulating the research on perovskite oxide thin films. Moreover, exploring the preparation of these materials with the use of cost-efficient and scalable solution-based techniques is a promising approach to extract their full potential. Herein, we present the design of a chemical route, based on metal nitrate precursors, for the preparation of pure phase La0.75Sr0.25CrO3 (LSCO) thin films to be used as a p-type transparent conductive electrode. Different solution chemistries have been evaluated to ultimately obtain dense, epitaxial, and almost relaxed LSCO films. Optical characterization of the optimized LSCO films reveals promising high transparency with ∼67% transmittance while room temperature resistivity values are 1.4 Ω·cm. It is suggested that the presence of structural defects, i.e., antiphase boundaries and misfit dislocations, affects the electrical behavior of LSCO films. Monochromated electron energy loss spectroscopy allowed changes in the electronic structure in LSCO films to be determined, revealing the creation of Cr4+ and unoccupied states at the O 2p upon Sr-doping. This work offers a new venue to prepare and further investigate cost-effective functional perovskite oxides with potential to be used as p-type transparent conducting electrodes and be easily integrated in many oxide heterostructures.
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Affiliation(s)
- Pamela Machado
- Institut
de Ciència de Materials de Barcelona ICMAB-CSIC, Campus UAB, Bellaterra 08193, Spain
| | - Roger Guzmán
- School
of Physical Sciences, University of Chinese
Academy of Sciences, Beijing 100049, China
| | - Ramon J. Morera
- Institut
de Ciència de Materials de Barcelona ICMAB-CSIC, Campus UAB, Bellaterra 08193, Spain
| | - Jordi Alcalà
- Institut
de Ciència de Materials de Barcelona ICMAB-CSIC, Campus UAB, Bellaterra 08193, Spain
| | - Anna Palau
- Institut
de Ciència de Materials de Barcelona ICMAB-CSIC, Campus UAB, Bellaterra 08193, Spain
| | - Wu Zhou
- School
of Physical Sciences, University of Chinese
Academy of Sciences, Beijing 100049, China
| | - Mariona Coll
- Institut
de Ciència de Materials de Barcelona ICMAB-CSIC, Campus UAB, Bellaterra 08193, Spain
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4
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Chen Y, Yuan X, Shan S, Zhang C, Liu R, Zhang X, Zhuang W, Chen Y, Xu Y, Zhang R, Wang X. Significant Reduction of the Dead Layers by the Strain Release in La 0.7Sr 0.3MnO 3 Heterostructures. ACS APPLIED MATERIALS & INTERFACES 2022; 14:39673-39678. [PMID: 35984645 DOI: 10.1021/acsami.2c12899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Great efforts have been devoted to exploring the emergent phenomena occurring in heterostructures of correlated oxides. However, the presence of both magnetic and electrical dead layers in functional oxide films generally obstructs the device functionalization and miniaturization. Here, we demonstrate an effective strategy to significantly reduce the thickness of dead layers in a prototypical correlated oxide system, La0.7Sr0.3MnO3 (LSMO) grown on LaAlO3 (LAO) substrates, via strain engineering by inserting a Sr3Al2O6 buffer layer with a different thickness at heterointerfaces. In this way, the thicknesses of the magnetic and electrical dead layers of LSMO films on the LAO substrates notably decrease from 8 to 4 unit cells and from 13 to 9 unit cells, respectively. Our results provide a convenient method to minimize or even eliminate the dead layers of correlated oxides through the interfacial strain engineering, which has potential applications in nanoscale oxide spintronic devices.
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Affiliation(s)
- Yongda Chen
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Xiao Yuan
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Siqi Shan
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Chong Zhang
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Ruxin Liu
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Xu Zhang
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Wenzhuo Zhuang
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Yequan Chen
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Yongbing Xu
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Rong Zhang
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Xuefeng Wang
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, P. R. China
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5
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Chakrapani V, Wang C, Wang Q, Smieszek N. Direct Determination of Mn Valence States in Mixed‐valent Manganates by Photoluminescence Spectroscopy. SURF INTERFACE ANAL 2022. [DOI: 10.1002/sia.7144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Vidhya Chakrapani
- Howard P. Isermann Department of Chemical and Biological Engineering Rensselaer Polytechnic Institute Troy New York United States
| | - Chenying Wang
- Howard P. Isermann Department of Chemical and Biological Engineering Rensselaer Polytechnic Institute Troy New York United States
| | - Qi Wang
- Howard P. Isermann Department of Chemical and Biological Engineering Rensselaer Polytechnic Institute Troy New York United States
| | - Nicholas Smieszek
- Howard P. Isermann Department of Chemical and Biological Engineering Rensselaer Polytechnic Institute Troy New York United States
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6
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Chaluvadi SK, Polewczyk V, Petrov AY, Vinai G, Braglia L, Diez JM, Pierron V, Perna P, Mechin L, Torelli P, Orgiani P. Electronic Properties of Fully Strained La 1-x Sr x MnO 3 Thin Films Grown by Molecular Beam Epitaxy (0.15 ≤ x ≤ 0.45). ACS OMEGA 2022; 7:14571-14578. [PMID: 35557663 PMCID: PMC9088787 DOI: 10.1021/acsomega.1c06529] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 02/04/2022] [Indexed: 06/15/2023]
Abstract
The structural, electronic, and magnetic properties of Sr-hole-doped epitaxial La1-x Sr x MnO3 (0.15 ≤ x ≤ 0.45) thin films deposited using the molecular beam epitaxy technique on 4° vicinal STO (001) substrates are probed by the combination of X-ray diffraction and various synchrotron-based spectroscopy techniques. The structural characterizations evidence a significant shift in the LSMO (002) peak to the higher diffraction angles owing to the increase in Sr doping concentrations in thin films. The nature of the LSMO Mn mixed-valence state was estimated from X-ray photoemission spectroscopy together with the relative changes in the Mn L2,3 edges observed in X-ray absorption spectroscopy (XAS), both strongly affected by doping. CTM4XAS simulations at the XAS Mn L2,3 edges reveal the combination of epitaxial strain, and different MnO6 crystal field splitting give rise to a peak at ∼641 eV. The observed changes in the occupancy of the eg and the t2g orbitals as well as their binding energy positions toward the Fermi level with hole doping are discussed. The room-temperature magnetic properties were probed at the end by circular dichroism.
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Affiliation(s)
- Sandeep Kumar Chaluvadi
- Istituto
Officina dei Materiali (IOM)−CNR, Laboratorio TASC, Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Vincent Polewczyk
- Istituto
Officina dei Materiali (IOM)−CNR, Laboratorio TASC, Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Aleksandr Yu Petrov
- Istituto
Officina dei Materiali (IOM)−CNR, Laboratorio TASC, Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Giovanni Vinai
- Istituto
Officina dei Materiali (IOM)−CNR, Laboratorio TASC, Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Luca Braglia
- Istituto
Officina dei Materiali (IOM)−CNR, Laboratorio TASC, Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | | | - Victor Pierron
- Normandie
Univ, UNICAEN, ENSICAEN, CNRS, GREYC (UMR 6072), 14000 Caen, France
| | - Paolo Perna
- IMDEA-Nanociencia, Campus de Cantoblanco, 28049 Madrid, Spain
| | - Laurence Mechin
- Normandie
Univ, UNICAEN, ENSICAEN, CNRS, GREYC (UMR 6072), 14000 Caen, France
| | - Piero Torelli
- Istituto
Officina dei Materiali (IOM)−CNR, Laboratorio TASC, Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Pasquale Orgiani
- Istituto
Officina dei Materiali (IOM)−CNR, Laboratorio TASC, Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
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7
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Rajak P, Knez D, Chaluvadi SK, Orgiani P, Rossi G, Méchin L, Ciancio R. Evidence of Mn-Ion Structural Displacements Correlated with Oxygen Vacancies in La 0.7Sr 0.3MnO 3 Interfacial Dead Layers. ACS APPLIED MATERIALS & INTERFACES 2021; 13:55666-55675. [PMID: 34758616 DOI: 10.1021/acsami.1c15599] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The properties of half-metallic manganite thin films depend on the composition and structure in the atomic scale, and consequently, their potential functional behavior can only be based on fine structure characterization. By combining advanced transmission electron microscopy, electron energy loss spectroscopy, density functional theory calculations, and multislice image simulations, we obtained evidence of a 7 nm-thick interface layer in La0.7Sr0.3MnO3 (LSMO) thin films, compatible with the formation of well-known dead layers in manganites, with an elongated out-of-plane lattice parameter and structural and electronic properties well distinguished from the bulk of the film. We observed, for the first time, a structural shift of Mn ions coupled with oxygen vacancies and a reduced Mn valence state within such layer. Understanding the correlation between oxygen vacancies, the Mn oxidation state, and Mn-ion displacements is a prerequisite to engineer the magnetotransport properties of LSMO thin films.
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Affiliation(s)
- Piu Rajak
- Istituto Officina dei Materiali-CNR, Area Science Park, S.S.14, km 163.5, 34149 Trieste, Italy
| | - Daniel Knez
- Institute of Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria
| | - Sandeep Kumar Chaluvadi
- Istituto Officina dei Materiali-CNR, Area Science Park, S.S.14, km 163.5, 34149 Trieste, Italy
| | - Pasquale Orgiani
- Istituto Officina dei Materiali-CNR, Area Science Park, S.S.14, km 163.5, 34149 Trieste, Italy
- CNR-SPIN, UOS Salerno, 84084 Fisciano, Salerno, Italy
| | - Giorgio Rossi
- Istituto Officina dei Materiali-CNR, Area Science Park, S.S.14, km 163.5, 34149 Trieste, Italy
- Dipartimento di Fisica, Università degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy
| | - Laurence Méchin
- Normandie University, UNICAEN, ENSICAEN, CNRS, GREYC, 14000 Caen, France
| | - Regina Ciancio
- Istituto Officina dei Materiali-CNR, Area Science Park, S.S.14, km 163.5, 34149 Trieste, Italy
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Wong HF, Ng SM, Zhang W, Liu YK, Wong PKJ, Tang CS, Lam KK, Zhao XW, Meng ZG, Fei LF, Cheng WF, Nordheim DV, Wong WY, Wang ZR, Ploss B, Dai JY, Mak CL, Wee ATS, Leung CW. Modulating Magnetism in Ferroelectric Polymer-Gated Perovskite Manganite Films with Moderate Gate Pulse Chains. ACS APPLIED MATERIALS & INTERFACES 2020; 12:56541-56548. [PMID: 33283518 DOI: 10.1021/acsami.0c14172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Most previous attempts on achieving electric-field manipulation of ferromagnetism in complex oxides, such as La0.66Sr0.33MnO3 (LSMO), are based on electrostatically induced charge carrier changes through high-k dielectrics or ferroelectrics. Here, the use of a ferroelectric copolymer, polyvinylidene fluoride with trifluoroethylene [P(VDF-TrFE)], as a gate dielectric to successfully modulate the ferromagnetism of the LSMO thin film in a field-effect device geometry is demonstrated. Specifically, through the application of low-voltage pulse chains inadequate to switch the electric dipoles of the copolymer, enhanced tunability of the oxide magnetic response is obtained, compared to that induced by ferroelectric polarization. Such observations have been attributed to electric field-induced oxygen vacancy accumulation/depletion in the LSMO layer upon the application of pulse chains, which is supported by surface-sensitive-characterization techniques, including X-ray photoelectron spectroscopy and X-ray magnetic circular dichroism. These techniques not only unveil the electrochemical nature of the mechanism but also establish a direct correlation between the oxygen vacancies created and subsequent changes to the valence states of Mn ions in LSMO. These demonstrations based on the pulsing strategy can be a viable route equally applicable to other functional oxides for the construction of electric field-controlled magnetic devices.
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Affiliation(s)
- Hon Fai Wong
- Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Sheung Mei Ng
- Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Wen Zhang
- School of Electronics and Information and School of Microelectronics, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an, Shaanxi 710072, China
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore
| | - Yu Kuai Liu
- Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Ping Kwan Johnny Wong
- School of Electronics and Information and School of Microelectronics, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an, Shaanxi 710072, China
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore
| | - Chi Sin Tang
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore
| | - Ka Kin Lam
- Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Xu Wen Zhao
- Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Zhen Gong Meng
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China
| | - Lin Feng Fei
- Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Wang Fai Cheng
- Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Danny von Nordheim
- Department of SciTec, University of Applied Sciences Jena, Carl-Zeiss-Promenade 2, 07743 Jena, Germany
| | - Wai Yeung Wong
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Zong Rong Wang
- State Key Lab of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Bernd Ploss
- Department of SciTec, University of Applied Sciences Jena, Carl-Zeiss-Promenade 2, 07743 Jena, Germany
| | - Ji-Yan Dai
- Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Chee Leung Mak
- Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Andrew Thye Shen Wee
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore
| | - Chi Wah Leung
- Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
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9
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Franceschi G, Schmid M, Diebold U, Riva M. Movable holder for a quartz crystal microbalance for exact growth rates in pulsed laser deposition. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:065003. [PMID: 32611011 DOI: 10.1063/5.0007643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Accepted: 05/29/2020] [Indexed: 06/11/2023]
Abstract
Controlling the amount of material deposited by pulsed laser deposition (PLD) down to fractions of one atomic layer is crucial for nanoscale technologies based on thin-film heterostructures. Albeit unsurpassed for measuring growth rates with high accuracy, the quartz crystal microbalance (QCM) suffers from some limitations when applied to PLD. The strong directionality of the PLD plasma plume and its pronounced dependence on deposition parameters (e.g., background pressure and fluence) require that the QCM is placed at the same position as the substrate during growth. However, QCM sensors are commonly fixed off to one side of the substrate. This also entails fast degradation of the crystal, as it is constantly exposed to the ablated material. The design for a movable QCM holder discussed in this work overcomes these issues. The holder is compatible with standard transfer arms, enabling easy insertion and transfer between a PLD chamber and other adjoining vacuum chambers. The QCM can be placed at the same position as the substrate during PLD growth. Its resonance frequency is measured in vacuum at any location where it can be in contact with an electrical feedthrough, before and after deposition. We tested the design for the deposition of hematite (Fe2O3), comparing the rates derived from the QCM and from reflection high-energy electron diffraction oscillations during homoepitaxial growth.
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Affiliation(s)
- Giada Franceschi
- Institute of Applied Physics, TU Wien, Wiedner Hauptstraße 8-10/E134, 1040 Wien, Austria
| | - Michael Schmid
- Institute of Applied Physics, TU Wien, Wiedner Hauptstraße 8-10/E134, 1040 Wien, Austria
| | - Ulrike Diebold
- Institute of Applied Physics, TU Wien, Wiedner Hauptstraße 8-10/E134, 1040 Wien, Austria
| | - Michele Riva
- Institute of Applied Physics, TU Wien, Wiedner Hauptstraße 8-10/E134, 1040 Wien, Austria
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