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Boergens KM, Wildenberg G, Li R, Lambert L, Moradi A, Stam G, Tromp R, van der Molen SJ, King SB, Kasthuri N. Photoemission electron microscopy for connectomics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.05.556423. [PMID: 37771915 PMCID: PMC10525389 DOI: 10.1101/2023.09.05.556423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
Detailing the physical basis of neural circuits with large-volume serial electron microscopy (EM), 'connectomics', has emerged as an invaluable tool in the neuroscience armamentarium. However, imaging synaptic resolution connectomes is currently limited to either transmission electron microscopy (TEM) or scanning electron microscopy (SEM). Here, we describe a third way, using photoemission electron microscopy (PEEM) which illuminates ultra-thin brain slices collected on solid substrates with UV light and images the photoelectron emission pattern with a wide-field electron microscope. PEEM works with existing sample preparations for EM and routinely provides sufficient resolution and contrast to reveal myelinated axons, somata, dendrites, and sub-cellular organelles. Under optimized conditions, PEEM provides synaptic resolution; and simulation and experiments show that PEEM can be transformatively fast, at Gigahertz pixel rates. We conclude that PEEM imaging leverages attractive aspects of SEM and TEM, namely reliable sample collection on robust substrates combined with fast wide-field imaging, and could enable faster data acquisition for next-generation circuit mapping.
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2
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Winchester AJ, Anderson TJ, Hite JK, Elmquist RE, Pookpanratana S. Methodology and implementation of a tunable deep-ultraviolet laser source for photoemission electron microscopy. Ultramicroscopy 2023; 253:113819. [PMID: 37549583 DOI: 10.1016/j.ultramic.2023.113819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 06/21/2023] [Accepted: 07/25/2023] [Indexed: 08/09/2023]
Abstract
Photoemission electron microscopy (PEEM) is a unique and powerful tool for studying the electronic properties of materials and surfaces. However, it requires intense and well-controlled light sources with photon energies ranging from the UV to soft X-rays for achieving high spatial resolution and image contrast. Traditionally, many PEEMs were installed at synchrotron light sources to access intense and tunable soft X-rays. More recently, the maturation of solid-state lasers has opened a new avenue for laboratory-based PEEMs using laser-based UV light at lower photon energies. Here, we report on the characteristics of a laser-based UV light source that was recently integrated with a PEEM instrument. The system consists of a high repetition rate, tunable wavelength laser coupled to a harmonics generation module, which generates deep-UV radiation from 192 nm to 210 nm. We comment on the spectral characteristics and overall laser system stability, as well as on the effects of space charge within the PEEM microscope at high UV laser fluxes. Further, we show an example of imaging on gallium nitride, where the higher UV photon energy and flux of the laser provides considerably improved image quality, compared to a conventional light source. These results demonstrate the capabilities of laser-based UV light sources for advancing laboratory-based PEEMs.
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Affiliation(s)
- Andrew J Winchester
- Nanoscale Device and Characterization Division, National Institute of Standards and Technology, Gaithersburg, MD, United States
| | - Travis J Anderson
- Electronics Science and Technology Division, U.S. Naval Research Laboratory, Washington, DC, United States
| | - Jennifer K Hite
- Electronics Science and Technology Division, U.S. Naval Research Laboratory, Washington, DC, United States
| | - Randolph E Elmquist
- Quantum Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD, United States
| | - Sujitra Pookpanratana
- Nanoscale Device and Characterization Division, National Institute of Standards and Technology, Gaithersburg, MD, United States.
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3
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Khaliq MW, Álvarez JM, Camps A, González N, Ferrer J, Martinez-Carboneres A, Prat J, Ruiz-Gómez S, Niño MA, Macià F, Aballe L, Foerster M. GHz sample excitation at the ALBA-PEEM. Ultramicroscopy 2023; 250:113757. [PMID: 37207610 DOI: 10.1016/j.ultramic.2023.113757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 04/14/2023] [Accepted: 05/08/2023] [Indexed: 05/21/2023]
Abstract
We describe a setup that is used for high-frequency electrical sample excitation in a cathode lens electron microscope with the sample stage at high voltage as used in many synchrotron light sources. Electrical signals are transmitted by dedicated high-frequency components to the printed circuit board supporting the sample. Sub-miniature push-on connectors (SMP) are used to realize the connection in the ultra-high vacuum chamber, bypassing the standard feedthrough. A bandwidth up to 4 GHz with -6 dB attenuation was measured at the sample position, which allows to apply sub-nanosecond pulses. We describe different electronic sample excitation schemes and demonstrate a spatial resolution of 56 nm employing the new setup.
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Affiliation(s)
- Muhammad Waqas Khaliq
- ALBA Synchrotron Light Facility, Carrer de la Llum, 2 - 26, Cerdanyola del Vallés, 08290 Barcelona, Spain; Department of Condensed Matter Physics, University of Barcelona, Barcelona, 08028 Spain.
| | - José M Álvarez
- ALBA Synchrotron Light Facility, Carrer de la Llum, 2 - 26, Cerdanyola del Vallés, 08290 Barcelona, Spain
| | - Antonio Camps
- ALBA Synchrotron Light Facility, Carrer de la Llum, 2 - 26, Cerdanyola del Vallés, 08290 Barcelona, Spain
| | - Nahikari González
- ALBA Synchrotron Light Facility, Carrer de la Llum, 2 - 26, Cerdanyola del Vallés, 08290 Barcelona, Spain
| | - José Ferrer
- ALBA Synchrotron Light Facility, Carrer de la Llum, 2 - 26, Cerdanyola del Vallés, 08290 Barcelona, Spain
| | | | - Jordi Prat
- ALBA Synchrotron Light Facility, Carrer de la Llum, 2 - 26, Cerdanyola del Vallés, 08290 Barcelona, Spain
| | - Sandra Ruiz-Gómez
- Max Planck Institute for Chemical Physics of Solids, Noethnitzer Str. 40, 01187 Dresden, Germany
| | - Miguel Angel Niño
- ALBA Synchrotron Light Facility, Carrer de la Llum, 2 - 26, Cerdanyola del Vallés, 08290 Barcelona, Spain
| | - Ferran Macià
- Department of Condensed Matter Physics, University of Barcelona, Barcelona, 08028 Spain; Institute of Nanoscience and Nanotechnology (IN2UB), University of Barcelona, 08028 Barcelona, Spain
| | - Lucia Aballe
- ALBA Synchrotron Light Facility, Carrer de la Llum, 2 - 26, Cerdanyola del Vallés, 08290 Barcelona, Spain
| | - Michael Foerster
- ALBA Synchrotron Light Facility, Carrer de la Llum, 2 - 26, Cerdanyola del Vallés, 08290 Barcelona, Spain.
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4
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Niu Y, Vinogradov N, Preobrajenski A, Struzzi C, Sarpi B, Zhu L, Golias E, Zakharov A. MAXPEEM: a spectromicroscopy beamline at MAX IV laboratory. JOURNAL OF SYNCHROTRON RADIATION 2023; 30:468-478. [PMID: 36891861 PMCID: PMC10000796 DOI: 10.1107/s160057752300019x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 01/09/2023] [Indexed: 06/13/2023]
Abstract
MAXPEEM, a dedicated photoemission electron microscopy beamline at MAX IV Laboratory, houses a state-of-the-art aberration-corrected spectroscopic photoemission and low-energy electron microscope (AC-SPELEEM). This powerful instrument offers a wide range of complementary techniques providing structural, chemical and magnetic sensitivities with a single-digit nanometre spatial resolution. The beamline can deliver a high photon flux of ≥1015 photons s-1 (0.1% bandwidth)-1 in the range 30-1200 eV with full control of the polarization from an elliptically polarized undulator. The microscope has several features which make it unique from similar instruments. The X-rays from the synchrotron pass through the first beam separator and impinge the surface at normal incidence. The microscope is equipped with an energy analyzer and an aberration corrector which improves both the resolution and the transmission compared with standard microscopes. A new fiber-coupled CMOS camera features an improved modulation transfer function, dynamic range and signal-to-noise ratio compared with the traditional MCP-CCD detection system.
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Affiliation(s)
- Yuran Niu
- MAX IV Laboratory, Lund University, Box 118, 22100 Lund, Sweden
| | | | | | - Claudia Struzzi
- MAX IV Laboratory, Lund University, Box 118, 22100 Lund, Sweden
| | - Brice Sarpi
- MAX IV Laboratory, Lund University, Box 118, 22100 Lund, Sweden
| | - Lin Zhu
- MAX IV Laboratory, Lund University, Box 118, 22100 Lund, Sweden
| | | | - Alexei Zakharov
- MAX IV Laboratory, Lund University, Box 118, 22100 Lund, Sweden
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5
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Zheng W, Jiang P, Zhang L, Wang Y, Sun Q, Liu Y, Gong Q, Wu C. Ultrafast extreme ultraviolet photoemission electron microscope. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:043709. [PMID: 34243459 DOI: 10.1063/5.0047076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 03/27/2021] [Indexed: 06/13/2023]
Abstract
Here, we report our newly built table-top ultrafast extreme ultraviolet (EUV) photoemission electron microscope. The coherent ultrafast EUV light is served by a single order harmonic, which is generated by the interaction between the intense 800-nm femtosecond laser and noble gases in the hollow core fiber. The required order of the harmonic is selected out by a single grating in the off-plane mount and focused on the sample in the ultrahigh vacuum chamber of the photoemission electron microscope. Using metal gold and copper samples, the spatial resolution is calibrated to be better than 50 nm and the energy resolution is calibrated to be better than 300 meV. This microscope provides an advanced tool for studying electron dynamics covering the full Brillouin zone of solid materials with ultrahigh time, space, and energy resolution.
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Affiliation(s)
- Wei Zheng
- State Key Laboratory for Mesoscopic Physics and Frontiers Science, Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Pengzuo Jiang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science, Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Linfeng Zhang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science, Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Yang Wang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science, Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Quan Sun
- Yangtze Delta Institute of Optoelectronics, Peking University, Nantong, Jiangsu 226010, China
| | - Yunquan Liu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science, Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Qihuang Gong
- State Key Laboratory for Mesoscopic Physics and Frontiers Science, Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Chengyin Wu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science, Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing 100871, China
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6
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King PDC, Picozzi S, Egdell RG, Panaccione G. Angle, Spin, and Depth Resolved Photoelectron Spectroscopy on Quantum Materials. Chem Rev 2021; 121:2816-2856. [PMID: 33346644 DOI: 10.1021/acs.chemrev.0c00616] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The role of X-ray based electron spectroscopies in determining chemical, electronic, and magnetic properties of solids has been well-known for several decades. A powerful approach is angle-resolved photoelectron spectroscopy, whereby the kinetic energy and angle of photoelectrons emitted from a sample surface are measured. This provides a direct measurement of the electronic band structure of crystalline solids. Moreover, it yields powerful insights into the electronic interactions at play within a material and into the control of spin, charge, and orbital degrees of freedom, central pillars of future solid state science. With strong recent focus on research of lower-dimensional materials and modified electronic behavior at surfaces and interfaces, angle-resolved photoelectron spectroscopy has become a core technique in the study of quantum materials. In this review, we provide an introduction to the technique. Through examples from several topical materials systems, including topological insulators, transition metal dichalcogenides, and transition metal oxides, we highlight the types of information which can be obtained. We show how the combination of angle, spin, time, and depth-resolved experiments are able to reveal "hidden" spectral features, connected to semiconducting, metallic and magnetic properties of solids, as well as underlining the importance of dimensional effects in quantum materials.
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Affiliation(s)
- Phil D C King
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, United Kingdom
| | - Silvia Picozzi
- Consiglio Nazionale delle Ricerche, CNR-SPIN, Via dei Vestini 31, Chieti 66100, Italy
| | - Russell G Egdell
- Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Giancarlo Panaccione
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, Km 163.5, I-34149 Trieste, Italy
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7
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Ning Y, Li Y, Wang C, Li R, Zhang F, Zhang S, Wang Z, Yang F, Zong N, Peng Q, Xu Z, Wang X, Li R, Breitschaft M, Hagen S, Schaff O, Fu Q, Bao X. Tunable deep ultraviolet laser based near ambient pressure photoemission electron microscope for surface imaging in the millibar regime. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:113704. [PMID: 33261460 DOI: 10.1063/5.0016242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 11/01/2020] [Indexed: 06/12/2023]
Abstract
A newly developed instrument comprising a near ambient pressure (NAP) photoemission electron microscope (PEEM) and a tunable deep ultraviolet (DUV) laser source is described. This NAP-PEEM instrument enables dynamic imaging of solid surfaces in gases at pressures up to 1 mbar. A diode laser (976 nm) can illuminate a sample from the backside for in situ heating in gases up to 1200 K in minutes. The DUV laser with a tunable wavelength between 175 nm and 210 nm is perpendicularly incident onto the sample surface for PEEM imaging of a wide spectrum of solids with different surface work functions. Using this setup, we have first demonstrated spatiotemporal oscillation patterns of CO oxidation reaction on Pt(110) from high vacuum to NAPs and gas-induced restructuring of metal nanostructures in millibar gases. The new facility promises important applications in heterogeneous catalysis, electrochemical devices, and other surface processes under nearly working conditions.
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Affiliation(s)
- Yanxiao Ning
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Yifan Li
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Chao Wang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Rongtan Li
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Fengfeng Zhang
- Research Center for Laser Physics and Technology, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Shenjin Zhang
- Research Center for Laser Physics and Technology, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Zhimin Wang
- Research Center for Laser Physics and Technology, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Feng Yang
- Research Center for Laser Physics and Technology, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Nan Zong
- Research Center for Laser Physics and Technology, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Qinjun Peng
- Research Center for Laser Physics and Technology, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Zuyan Xu
- Research Center for Laser Physics and Technology, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaoyang Wang
- Beijing Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Rukang Li
- Beijing Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | | | | | - Oliver Schaff
- SPECS Surface Nano Analysis GmbH, Berlin 13355, Germany
| | - Qiang Fu
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Xinhe Bao
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
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8
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Rullik L, Evertsson J, Johansson N, Bertram F, Nilsson J, Zakharov AA, Mikkelsen A, Lundgren E. Surface oxide development on aluminum alloy 6063 during heat treatment. SURF INTERFACE ANAL 2019. [DOI: 10.1002/sia.6616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Lisa Rullik
- Division of Synchrotron Radiation Research, Department of PhysicsLund University Lund Sweden
| | - Jonas Evertsson
- Division of Synchrotron Radiation Research, Department of PhysicsLund University Lund Sweden
| | | | - Florian Bertram
- Deutsches Elektronen‐Synchrotron (DESY)Photon Science Hamburg Germany
| | | | | | - Anders Mikkelsen
- Division of Synchrotron Radiation Research, Department of PhysicsLund University Lund Sweden
| | - Edvin Lundgren
- Division of Synchrotron Radiation Research, Department of PhysicsLund University Lund Sweden
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9
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Imaging properties of hemispherical electrostatic energy analyzers for high resolution momentum microscopy. Ultramicroscopy 2019; 206:112815. [PMID: 31325896 DOI: 10.1016/j.ultramic.2019.112815] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 07/07/2019] [Indexed: 11/20/2022]
Abstract
Hemispherical deflection analyzers are the most widely used energy filters for state-of-the-art electron spectroscopy. Due to the high spherical symmetry, they are also well suited as imaging energy filters for electron microscopy. Here, we review the imaging properties of hemispherical deflection analyzers with emphasis on the application for cathode lens microscopy. In particular, it turns out that aberrations, in general limiting the image resolution, cancel out at the entrance and exit of the analyzer. This finding allows more compact imaging energy filters for momentum microscopy or photoelectron emission microscopy. For instance, high resolution imaging is possible, using only a single hemisphere. Conversely, a double pass hemispherical analyzer can double the energy dispersion, which means it can double the energy resolution at certain transmission, or can multiply the transmission at certain energy resolution.
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10
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Zhao YC, Lyu HC, Yang G, Dong BW, Qi J, Zhang JY, Zhu ZZ, Sun Y, Yu GH, Jiang Y, Wei HX, Wang J, Lu J, Wang ZH, Cai JW, Shen BG, Zhan WS, Yang F, Zhang SJ, Wang SG. Direct observation of magnetic contrast obtained by photoemission electron microscopy with deep ultra-violet laser excitation. Ultramicroscopy 2019; 202:156-162. [PMID: 31063898 DOI: 10.1016/j.ultramic.2019.04.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 03/31/2019] [Accepted: 04/17/2019] [Indexed: 11/28/2022]
Abstract
Magnetic circular dichroism (MCD) and magnetic linear dichroism (MLD) have been investigated in a photoemission electron microscopy (PEEM) system excited by a deep ultra-violet (DUV) laser (with λ = 177.3 nm and hυ = 7.0 eV) for the first time. High resolution PEEM magnetic images (down to 43.2 nm) were directly obtained on a (001)-oriented magnetic FePt film surface with a circularly-polarized light under normal incidence. Furthermore, a stepped Cr seeding layer was applied to induce the formation of large-area epitaxial FePt films with (001) and (111) two orientations, where MLD with large asymmetry was observed in the transition area of two phases. It demonstrates that DUV laser can be a powerful source for high resolution magnetic imaging in the laboratory in absence of synchrotron facilities.
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Affiliation(s)
- Y C Zhao
- State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - H C Lyu
- State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - G Yang
- State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - B W Dong
- State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - J Qi
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - J Y Zhang
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Z Z Zhu
- State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Y Sun
- State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - G H Yu
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Y Jiang
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - H X Wei
- State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - J Wang
- State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - J Lu
- State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Z H Wang
- State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - J W Cai
- State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - B G Shen
- State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - W S Zhan
- State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - F Yang
- Key Lab of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - S J Zhang
- Key Lab of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - S G Wang
- State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China.
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11
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Aballe L, Foerster M, Cabrejo M, Prat J, Pittana P, Sergo R, Lucian M, Barnaba M, Menteş TO, Locatelli A. Pulse picking in synchrotron-based XPEEM. Ultramicroscopy 2019; 202:10-17. [PMID: 30928638 DOI: 10.1016/j.ultramic.2019.03.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 03/18/2019] [Indexed: 10/27/2022]
Abstract
We report on a simple and cost-effective device for high-speed gating in photoemission electron microscopy (PEEM) with pulsed photon sources. This device is based on miniaturized electrode plates, which deflect the photoelectron beam inside the imaging column of the microscope so that it is either accepted or blocked in its path towards the detector. The gating device is optimized for installation on the Elmitec SPELEEM III microscope. Due to the compact design, it can be driven by voltage pulses of low amplitude (few volts), delivered by commercially available signal generators. Most notably, our device allows for stroboscopic data collection with on-time of less than 10 ns and at a rate in the range from 1 MHz to 250 MHz, making it suitable for usage in both hybrid and standard multi-bunch operation of the synchrotron ring. We demonstrate applications of pump-probe imaging at high lateral resolution, namely magnetic imaging and PEEM imaging of surface acoustic waves.
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Affiliation(s)
- Lucia Aballe
- ALBA Synchrotron, Carrer de la llum 2-26, 08290 Cerdanyola del Valles, Spain.
| | - Michael Foerster
- ALBA Synchrotron, Carrer de la llum 2-26, 08290 Cerdanyola del Valles, Spain
| | - Meritxell Cabrejo
- ALBA Synchrotron, Carrer de la llum 2-26, 08290 Cerdanyola del Valles, Spain
| | - Jordi Prat
- ALBA Synchrotron, Carrer de la llum 2-26, 08290 Cerdanyola del Valles, Spain
| | - Paolo Pittana
- Elettra-Sincrotrone Trieste, Strada Statale 14 - km 163.5 in AREA Science Park, Basovizza, I-34149 Trieste, Italy
| | - Rudi Sergo
- Elettra-Sincrotrone Trieste, Strada Statale 14 - km 163.5 in AREA Science Park, Basovizza, I-34149 Trieste, Italy
| | - Matteo Lucian
- Elettra-Sincrotrone Trieste, Strada Statale 14 - km 163.5 in AREA Science Park, Basovizza, I-34149 Trieste, Italy
| | - Maurizio Barnaba
- Elettra-Sincrotrone Trieste, Strada Statale 14 - km 163.5 in AREA Science Park, Basovizza, I-34149 Trieste, Italy
| | - Tevfik Onur Menteş
- Elettra-Sincrotrone Trieste, Strada Statale 14 - km 163.5 in AREA Science Park, Basovizza, I-34149 Trieste, Italy
| | - Andrea Locatelli
- Elettra-Sincrotrone Trieste, Strada Statale 14 - km 163.5 in AREA Science Park, Basovizza, I-34149 Trieste, Italy.
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12
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Stifler CA, Wittig NK, Sassi M, Sun CY, Marcus MA, Birkedal H, Beniash E, Rosso KM, Gilbert PUPA. X-ray Linear Dichroism in Apatite. J Am Chem Soc 2018; 140:11698-11704. [DOI: 10.1021/jacs.8b05547] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Cayla A. Stifler
- Department of Physics, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Nina Kølln Wittig
- Department of Chemistry and iNANO, Aarhus University, Aarhus, 8000, Denmark
| | - Michel Sassi
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Chang-Yu Sun
- Department of Physics, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Matthew A. Marcus
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Henrik Birkedal
- Department of Chemistry and iNANO, Aarhus University, Aarhus, 8000, Denmark
| | - Elia Beniash
- Departments of Oral Biology and Bioengineering, Center for Craniofacial Regeneration, McGowan Institute for Regenerative Medicine, School of Dental Medicine, UPitt, Pittsburgh, Pennsylvania 15261, United States
| | - Kevin M. Rosso
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Pupa U. P. A. Gilbert
- Department of Physics, University of Wisconsin, Madison, Wisconsin 53706, United States
- Departments of Chemistry, Materials Science, and Geoscience, University of Wisconsin, Madison, Wisconsin 53706, United States
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13
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Quantifying redox-induced Schottky barrier variations in memristive devices via in operando spectromicroscopy with graphene electrodes. Nat Commun 2016; 7:12398. [PMID: 27539213 PMCID: PMC4992164 DOI: 10.1038/ncomms12398] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 06/29/2016] [Indexed: 01/15/2023] Open
Abstract
The continuing revolutionary success of mobile computing and smart devices calls for the development of novel, cost- and energy-efficient memories. Resistive switching is attractive because of, inter alia, increased switching speed and device density. On electrical stimulus, complex nanoscale redox processes are suspected to induce a resistance change in memristive devices. Quantitative information about these processes, which has been experimentally inaccessible so far, is essential for further advances. Here we use in operando spectromicroscopy to verify that redox reactions drive the resistance change. A remarkable agreement between experimental quantification of the redox state and device simulation reveals that changes in donor concentration by a factor of 2–3 at electrode-oxide interfaces cause a modulation of the effective Schottky barrier and lead to >2 orders of magnitude change in device resistance. These findings allow realistic device simulations, opening a route to less empirical and more predictive design of future memory cells. Resistive switching in metal oxides is related to the migration of donor defects. Here Baeumer et al. use in operando X-ray spectromicroscopy to quantify the doping locally and show that small local variations in the donor concentration result in large variations in the device resistance.
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14
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Liang Z, Yin Z, Yang H, Xiao Y, Hang W, Li J. Nanoscale surface analysis that combines scanning probe microscopy and mass spectrometry: A critical review. Trends Analyt Chem 2016. [DOI: 10.1016/j.trac.2015.07.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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15
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Taniuchi T, Kotani Y, Shin S. Ultrahigh-spatial-resolution chemical and magnetic imaging by laser-based photoemission electron microscopy. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:023701. [PMID: 25725846 DOI: 10.1063/1.4906755] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report the first experiments carried out on a new chemical and magnetic imaging system, which combines the high spatial resolution of a photoemission electron microscope (PEEM) with a continuous-wave deep-ultraviolet laser. Threshold photoemission is sensitive to the chemical and magnetic structures of the surface of materials. The spatial resolution of PEEM is limited by space charging when using pulsed photon sources as well as aberrations in the electron optics. We show that the use of a continuous-wave laser enabled us to overcome such a limit by suppressing the space-charge effect, allowing us to obtain a resolution of approximately 2.6 nm. With this system, we demonstrated the imaging of surface reconstruction domains on Si(001) by linear dichroism with normal incidence of the laser beam. We also succeeded in magnetic imaging of thin films with the use of magnetic circular dichroism near the Fermi level. The unique features of the ultraviolet laser will give us fast switching of the incident angles and polarizations of the photon source, which will be useful for the characterization of antiferromagnetic materials as well as ferromagnetic materials.
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Affiliation(s)
- Toshiyuki Taniuchi
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Yoshinori Kotani
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Shik Shin
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
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16
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Tromp RM. Catadioptric aberration correction in cathode lens microscopy. Ultramicroscopy 2014; 151:191-198. [PMID: 25458190 DOI: 10.1016/j.ultramic.2014.09.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 09/23/2014] [Accepted: 09/25/2014] [Indexed: 10/24/2022]
Abstract
In this paper I briefly review the use of electrostatic electron mirrors to correct the aberrations of the cathode lens objective lens in low energy electron microscope (LEEM) and photo electron emission microscope (PEEM) instruments. These catadioptric systems, combining electrostatic lens elements with a reflecting mirror, offer a compact solution, allowing simultaneous and independent correction of both spherical and chromatic aberrations. A comparison with catadioptric systems in light optics informs our understanding of the working principles behind aberration correction with electron mirrors, and may point the way to further improvements in the latter. With additional developments in detector technology, 1 nm spatial resolution in LEEM appears to be within reach.
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Affiliation(s)
- R M Tromp
- IBM T.J. Watson Research Center, PO Box 218, Yorktown Heights, NY 10598, USA; Kamerlingh Onnes Laboratory, Leiden Institute of Physics, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands
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17
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Patt M, Wiemann C, Weber N, Escher M, Gloskovskii A, Drube W, Merkel M, Schneider CM. Bulk sensitive hard x-ray photoemission electron microscopy. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:113704. [PMID: 25430117 DOI: 10.1063/1.4902141] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Hard x-ray photoelectron spectroscopy (HAXPES) has now matured into a well-established technique as a bulk sensitive probe of the electronic structure due to the larger escape depth of the highly energetic electrons. In order to enable HAXPES studies with high lateral resolution, we have set up a dedicated energy-filtered hard x-ray photoemission electron microscope (HAXPEEM) working with electron kinetic energies up to 10 keV. It is based on the NanoESCA design and also preserves the performance of the instrument in the low and medium energy range. In this way, spectromicroscopy can be performed from threshold to hard x-ray photoemission. The high potential of the HAXPEEM approach for the investigation of buried layers and structures has been shown already on a layered and structured SrTiO3 sample. Here, we present results of experiments with test structures to elaborate the imaging and spectroscopic performance of the instrument and show the capabilities of the method to image bulk properties. Additionally, we introduce a method to determine the effective attenuation length of photoelectrons in a direct photoemission experiment.
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Affiliation(s)
- M Patt
- Peter Grünberg Institute (PGI-6) and JARA-FIT, Research Center Jülich, D-52425 Jülich, Germany
| | - C Wiemann
- Peter Grünberg Institute (PGI-6) and JARA-FIT, Research Center Jülich, D-52425 Jülich, Germany
| | - N Weber
- Focus GmbH, Neukirchner Str. 2, D-65510 Hünstetten, Germany
| | - M Escher
- Focus GmbH, Neukirchner Str. 2, D-65510 Hünstetten, Germany
| | - A Gloskovskii
- DESY Photon Science, Deutsches Elektronen-Synchrotron, D-22603 Hamburg, Germany
| | - W Drube
- DESY Photon Science, Deutsches Elektronen-Synchrotron, D-22603 Hamburg, Germany
| | - M Merkel
- Focus GmbH, Neukirchner Str. 2, D-65510 Hünstetten, Germany
| | - C M Schneider
- Peter Grünberg Institute (PGI-6) and JARA-FIT, Research Center Jülich, D-52425 Jülich, Germany
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18
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Menteş TO, Zamborlini G, Sala A, Locatelli A. Cathode lens spectromicroscopy: methodology and applications. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2014; 5:1873-86. [PMID: 25383299 PMCID: PMC4222408 DOI: 10.3762/bjnano.5.198] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 09/25/2014] [Indexed: 05/28/2023]
Abstract
The implementation of imaging techniques with low-energy electrons at synchrotron laboratories allowed for significant advancement in the field of spectromicroscopy. The spectroscopic photoemission and low energy electron microscope, SPELEEM, is a notable example. We summarize the multitechnique capabilities of the SPELEEM instrument, reporting on the instrumental aspects and the latest developments on the technical side. We briefly review applications, which are grouped into two main scientific fields. The first one covers different aspects of graphene physics. In particular, we highlight the recent work on graphene/Ir(100). Here, SPELEEM was employed to monitor the changes in the electronic structure that occur for different film morphologies and during the intercalation of Au. The Au monolayer, which creeps under graphene from the film edges, efficiently decouples the graphene from the substrate lowering the Dirac energy from 0.42 eV to 0.1 eV. The second field combines magnetism studies at the mesoscopic length scale with self-organized systems featuring ordered nanostructures. This example highlights the possibility to monitor growth processes in real time and combine chemical characterization with X-ray magnetic circular dichroism-photoemission electron microscopy (XMCD-PEEM) magnetic imaging by using the variable photon polarization and energy available at the synchrotron source.
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Affiliation(s)
- T O Menteş
- Elettra - Sincrotrone Trieste S.C.p.A., Basovizza, Trieste 34149, Italy
| | - G Zamborlini
- Department of Physics, University of Trieste, Via Valerio 2, Trieste 34137, Italy
- Peter Grünberg Institute (PGI-6) and JARA-FIT, Research Center Jülich, 52425 Jülich, Germany
| | - A Sala
- Elettra - Sincrotrone Trieste S.C.p.A., Basovizza, Trieste 34149, Italy
| | - A Locatelli
- Elettra - Sincrotrone Trieste S.C.p.A., Basovizza, Trieste 34149, Italy
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19
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Rotenberg E, Bostwick A. microARPES and nanoARPES at diffraction-limited light sources: opportunities and performance gains. JOURNAL OF SYNCHROTRON RADIATION 2014; 21:1048-56. [PMID: 25177993 DOI: 10.1107/s1600577514015409] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 07/01/2014] [Indexed: 05/13/2023]
Abstract
The scientific opportunities for microARPES and nanoARPES techniques are discussed, and the benefits to these techniques at diffraction-limited light sources are presented, in particular the impact on spectromicroscopic ARPES (angle-resolved photoemission spectroscopy) of upgrading the Advanced Light Source to diffraction-limited performance. The most important consideration is whether the space-charge broadening, impacting the energy and momentum resolution, will limit the possible benefits for ARPES. Calculations of energy broadening due to space-charge effects will be presented over a wide range of parameters, and optimum conditions for ARPES will be discussed. The conclusion is that spectromicroscopic ARPES will greatly benefit from the advent of diffraction-limited light sources; space-charge broadening effects will not be a limiting factor.
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Affiliation(s)
- Eli Rotenberg
- Advanced Light Source, MS 6-2100, E. O. Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Aaron Bostwick
- Advanced Light Source, MS 6-2100, E. O. Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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20
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First experimental proof for aberration correction in XPEEM: Resolution, transmission enhancement, and limitation by space charge effects. Ultramicroscopy 2013; 126:23-32. [DOI: 10.1016/j.ultramic.2012.11.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 11/09/2012] [Accepted: 11/13/2012] [Indexed: 11/17/2022]
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21
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Man KL, Altman MS. Low energy electron microscopy and photoemission electron microscopy investigation of graphene. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:314209. [PMID: 22820702 DOI: 10.1088/0953-8984/24/31/314209] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Low energy electron microscopy (LEEM) and photoemission electron microscopy (PEEM) are two powerful techniques for the investigation of surfaces, thin films and surface supported nanostructures. In this review, we examine the contributions of these microscopy techniques to our understanding of graphene in recent years. These contributions have been made in studies of graphene on various metal and SiC surfaces and free-standing graphene. We discuss how the real-time imaging capability of LEEM facilitates a deeper understanding of the mechanisms of dynamic processes, such as growth and intercalation. Numerous examples also demonstrate how imaging and the various available complementary measurement capabilities, such as selected area or micro low energy electron diffraction (μLEED) and micro angle resolved photoelectron spectroscopy (μARPES), allow the investigation of local properties in spatially inhomogeneous graphene samples.
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Affiliation(s)
- K L Man
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
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22
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Barrett N, Conrad E, Winkler K, Krömker B. Dark field photoelectron emission microscopy of micron scale few layer graphene. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:083706. [PMID: 22938302 DOI: 10.1063/1.4746279] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We demonstrate dark field imaging in photoelectron emission microscopy (PEEM) of heterogeneous few layer graphene (FLG) furnace grown on SiC(000-1). Energy-filtered, threshold PEEM is used to locate distinct zones of FLG graphene. In each region, selected by a field aperture, the k-space information is imaged using appropriate transfer optics. By selecting the photoelectron intensity at a given wave vector and using the inverse transfer optics, dark field PEEM gives a spatial distribution of the angular photoelectron emission. In the results presented here, the wave vector coordinates of the Dirac cones characteristic of commensurate rotations of FLG on SiC(000-1) are selected providing a map of the commensurate rotations across the surface. This special type of contrast is therefore a method to map the spatial distribution of the local band structure and offers a new laboratory tool for the characterisation of technically relevant, microscopically structured matter.
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Affiliation(s)
- N Barrett
- IRAMIS/SPCSI/LENSIS, F-91191 Gif-sur-Yvette, France.
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23
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LEEM and UHV-PEEM: A retrospective. Ultramicroscopy 2012; 119:18-23. [DOI: 10.1016/j.ultramic.2011.09.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 08/30/2011] [Accepted: 09/03/2011] [Indexed: 11/18/2022]
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24
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Spectromicroscopy with Low-Energy Electrons: LEEM and XPEEM Studies at the Nanoscale. E-JOURNAL OF SURFACE SCIENCE AND NANOTECHNOLOGY 2011. [DOI: 10.1380/ejssnt.2011.72] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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