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Liu Y, Luchini A, Martí-Sánchez S, Koch C, Schuwalow S, Khan SA, Stankevič T, Francoual S, Mardegan JRL, Krieger JA, Strocov VN, Stahn J, Vaz CAF, Ramakrishnan M, Staub U, Lefmann K, Aeppli G, Arbiol J, Krogstrup P. Coherent Epitaxial Semiconductor-Ferromagnetic Insulator InAs/EuS Interfaces: Band Alignment and Magnetic Structure. ACS Appl Mater Interfaces 2020; 12:8780-8787. [PMID: 31877013 DOI: 10.1021/acsami.9b15034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Hybrid semiconductor-ferromagnetic insulator heterostructures are interesting due to their tunable electronic transport, self-sustained stray field, and local proximitized magnetic exchange. In this work, we present lattice-matched hybrid epitaxy of semiconductor-ferromagnetic insulator InAs/EuS heterostructures and analyze the atomic-scale structure and their electronic and magnetic characteristics. The Fermi level at the InAs/EuS interface is found to be close to the InAs conduction band and in the band gap of EuS, thus preserving the semiconducting properties. Both neutron and X-ray reflectivity measurements show that the overall ferromagnetic component is mainly localized in the EuS thin film with a suppression of the Eu moment in the EuS layer nearest the InAs and magnetic moments outside the detection limits on the pure InAs side. This work presents a step toward realizing defect-free semiconductor-ferromagnetic insulator epitaxial hybrids for spin-lifted quantum and spintronic applications without external magnetic fields.
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Affiliation(s)
- Yu Liu
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
| | | | - Sara Martí-Sánchez
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST , Campus UAB, Bellaterra , 08193 Barcelona , Catalonia , Spain
| | - Christian Koch
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST , Campus UAB, Bellaterra , 08193 Barcelona , Catalonia , Spain
| | - Sergej Schuwalow
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
| | - Sabbir A Khan
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
| | - Tomaš Stankevič
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
| | - Sonia Francoual
- Deutsches Elektronen-Synchrotron DESY , Hamburg 22603 , Germany
| | | | | | | | - Jochen Stahn
- Paul Scherrer Institute , CH-5232 Villigen , Switzerland
| | - Carlos A F Vaz
- Paul Scherrer Institute , CH-5232 Villigen , Switzerland
| | | | - Urs Staub
- Paul Scherrer Institute , CH-5232 Villigen , Switzerland
| | | | - Gabriel Aeppli
- Paul Scherrer Institute , CH-5232 Villigen , Switzerland
- ETH , CH-8093 Zürich , Switzerland
- EPFL , CH-1015 Lausanne , Switzerland
| | - Jordi Arbiol
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST , Campus UAB, Bellaterra , 08193 Barcelona , Catalonia , Spain
- ICREA , Pg. Lluís Companys 23 , 08010 Barcelona , Catalonia , Spain
| | - Peter Krogstrup
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
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Dzhigaev D, Stankevič T, Bi Z, Lazarev S, Rose M, Shabalin A, Reinhardt J, Mikkelsen A, Samuelson L, Falkenberg G, Feidenhans'l R, Vartanyants IA. X-ray Bragg Ptychography on a Single InGaN/GaN Core-Shell Nanowire. ACS Nano 2017; 11:6605-6611. [PMID: 28264155 DOI: 10.1021/acsnano.6b08122] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The future of solid-state lighting can be potentially driven by applications of InGaN/GaN core-shell nanowires. These heterostructures provide the possibility for fine-tuning of functional properties by controlling a strain state between mismatched layers. We present a nondestructive study of a single 400 nm-thick InGaN/GaN core-shell nanowire using two-dimensional (2D) X-ray Bragg ptychography (XBP) with a nanofocused X-ray beam. The XBP reconstruction enabled the determination of a detailed three-dimensional (3D) distribution of the strain in the particular nanowire using a model based on finite element method. We observed the strain induced by the lattice mismatch between the GaN core and InGaN shell to be in the range from -0.1% to 0.15% for an In concentration of 30%. The maximum value of the strain component normal to the facets was concentrated at the transition region between the main part of the nanowire and the GaN tip. In addition, a variation in misfit strain relaxation between the axial growth and in-plane directions was revealed.
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Affiliation(s)
- Dmitry Dzhigaev
- Deutsches Elektronen-Synchrotron DESY , Notkestraße 85, D-22607 Hamburg, Germany
| | - Tomaš Stankevič
- Niels Bohr Institute, University of Copenhagen , Blegdamsvej 17, 2100 Copenhagen, Denmark
| | - Zhaoxia Bi
- NanoLund, Department of Physics, Lund University , P.O. Box 118, SE-221 00 Lund, Sweden
| | - Sergey Lazarev
- Deutsches Elektronen-Synchrotron DESY , Notkestraße 85, D-22607 Hamburg, Germany
- National Research Tomsk Polytechnic University (TPU) , pr. Lenina 30, 634050 Tomsk, Russia
| | - Max Rose
- Deutsches Elektronen-Synchrotron DESY , Notkestraße 85, D-22607 Hamburg, Germany
| | - Anatoly Shabalin
- Deutsches Elektronen-Synchrotron DESY , Notkestraße 85, D-22607 Hamburg, Germany
| | - Juliane Reinhardt
- Deutsches Elektronen-Synchrotron DESY , Notkestraße 85, D-22607 Hamburg, Germany
| | - Anders Mikkelsen
- NanoLund, Department of Physics, Lund University , P.O. Box 118, SE-221 00 Lund, Sweden
| | - Lars Samuelson
- NanoLund, Department of Physics, Lund University , P.O. Box 118, SE-221 00 Lund, Sweden
| | - Gerald Falkenberg
- Deutsches Elektronen-Synchrotron DESY , Notkestraße 85, D-22607 Hamburg, Germany
| | - Robert Feidenhans'l
- Niels Bohr Institute, University of Copenhagen , Blegdamsvej 17, 2100 Copenhagen, Denmark
| | - Ivan A Vartanyants
- Deutsches Elektronen-Synchrotron DESY , Notkestraße 85, D-22607 Hamburg, Germany
- National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) , Kashirskoe shosse 31, 115409 Moscow, Russia
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Vogt U, Köhler D, Dickmann J, Rahomäki J, Parfeniukas K, Kubsky S, Alves F, Langlois F, Engblom C, Stankevič T. Moiré method for nanometer instability investigation of scanning hard x-ray microscopes. Opt Express 2017; 25:12188-12194. [PMID: 28786577 DOI: 10.1364/oe.25.012188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 04/22/2017] [Indexed: 06/07/2023]
Abstract
We present a Moiré method that can be used to investigate positional instabilities in a scanning hard x-ray microscope with nanometer precision. The development of diffraction-limited storage rings offering highly-brilliant synchrotron radiation and improvements of nanofocusing x-ray optics paves the way towards 3D nanotomography with 10 nm resolution or below. However, this trend demands improved designs of x-ray microscope instruments which should offer few-nm beam stabilities with respect to the sample. Our technique can measure the position of optics and sample stage relative to each other in the two directions perpendicular to the beam propagation in a scanning x-ray microscope using simple optical components and visible light. The usefulness of the method was proven by measuring short and long term instabilities of a zone-plate-optics-based prototype microscope. We think it can become an important tool for the characterization of scanning x-ray microscopes, especially prior to experiments with an actual x-ray beam.
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Stankevič T, Engblom C, Langlois F, Alves F, Lestrade A, Jobert N, Cauchon G, Vogt U, Kubsky S. Interferometric characterization of rotation stages for X-ray nanotomography. Rev Sci Instrum 2017; 88:053703. [PMID: 28571450 DOI: 10.1063/1.4983405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The field of three-dimensional multi-modal X-ray nanoimaging relies not only on high-brilliance X-rays but also on high-precision mechanics and position metrology. Currently available state-of-the-art linear and rotary drives can provide 3D position accuracy within tens to hundreds of nm, which is often insufficient for high resolution imaging with nanofocused X-ray beams. Motion errors are especially troublesome in the case of rotation drives and their correction is more complicated and relies on the metrology grade reference objects. Here we present a method which allows the characterisation and correction of the radial and angular errors of the rotary drives without the need for a highly accurate metrology object. The method is based on multi-probe error separation using fiber-laser interferometry and uses a standard cylindrical sample holder as a reference. The obtained runout and shape measurements are then used to perform the position corrections using additional drives. We demonstrate the results of the characterization for a piezo-driven small rotation stage. The error separation allowed us to measure the axis runout to be approximately ±1.25 μm, and with active runout compensation this could be reduced down to ±42 nm.
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Affiliation(s)
- Tomaš Stankevič
- MAX IV Laboratory, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden
| | - Christer Engblom
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin BP48, 91192 Gif-sur-Yvette, France
| | - Florent Langlois
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin BP48, 91192 Gif-sur-Yvette, France
| | - Filipe Alves
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin BP48, 91192 Gif-sur-Yvette, France
| | - Alain Lestrade
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin BP48, 91192 Gif-sur-Yvette, France
| | - Nicolas Jobert
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin BP48, 91192 Gif-sur-Yvette, France
| | - Gilles Cauchon
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin BP48, 91192 Gif-sur-Yvette, France
| | - Ulrich Vogt
- Biomedical and X-Ray Physics, KTH/Royal Institute of Technology, KTH-AlbaNova, SE-106 91 Stockholm, Sweden
| | - Stefan Kubsky
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin BP48, 91192 Gif-sur-Yvette, France
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Stankevič T, Hilner E, Seiboth F, Ciechonski R, Vescovi G, Kryliouk O, Johansson U, Samuelson L, Wellenreuther G, Falkenberg G, Feidenhans'l R, Mikkelsen A. Fast Strain Mapping of Nanowire Light-Emitting Diodes Using Nanofocused X-ray Beams. ACS Nano 2015; 9:6978-6984. [PMID: 26090689 DOI: 10.1021/acsnano.5b01291] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
X-ray nanobeams are unique nondestructive probes that allow direct measurements of the nanoscale strain distribution and composition inside the micrometer thick layered structures that are found in most electronic device architectures. However, the method is usually extremely time-consuming, and as a result, data sets are often constrained to a few or even single objects. Here we demonstrate that by special design of a nanofocused X-ray beam diffraction experiment we can (in a single 2D scan with no sample rotation) measure the individual strain and composition profiles of many structures in an array of upright standing nanowires. We make use of the observation that in the generic nanowire device configuration, which is found in high-speed transistors, solar cells, and light-emitting diodes, each wire exhibits very small degrees of random tilts and twists toward the substrate. Although the tilt and twist are very small, they give a new contrast mechanism between different wires. In the present case, we image complex nanowires for nanoLED fabrication and compare to theoretical simulations, demonstrating that this fast method is suitable for real nanostructured devices.
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Affiliation(s)
- Tomaš Stankevič
- †Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Emelie Hilner
- †Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Frank Seiboth
- ‡Technische Universität Dresden, D-01062 Dresden, Germany
| | | | | | - Olga Kryliouk
- ⊥Glo-USA, Inc., 1225 Bordeaux Drive, Sunnyvale, California 94089, United States
| | | | | | - Gerd Wellenreuther
- ¶Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607 Hamburg, Germany
| | - Gerald Falkenberg
- ¶Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607 Hamburg, Germany
| | - Robert Feidenhans'l
- †Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
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Heurlin M, Stankevič T, Mickevičius S, Yngman S, Lindgren D, Mikkelsen A, Feidenhans'l R, Borgström MT, Samuelson L. Structural Properties of wurtzite InP-InGaAs nanowire core-shell heterostructures. Nano Lett 2015; 15:2462-7. [PMID: 25714126 DOI: 10.1021/nl5049127] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We report on growth and characterization of wurtzite InP-In(1-x)Ga(x)As core-shell nanowire heterostructures. A range of nanowire structures with different Ga concentration in the shell was characterized with transmission electron microscopy and X-ray diffraction. We found that the main part of the nanowires has a pure wurtzite crystal structure, with occasional stacking faults occurring only at the top and bottom. This allowed us to determine the structural properties of wurtzite In(1-x)Ga(x)As. The InP-In(1-x)Ga(x)As core-shell nanowires show a triangular and hexagonal facet structure of {1100} and {101̅0} planes. X-ray diffraction measurements showed that the core and the shell are pseudomorphic along the c-axis, and the strained axial lattice constant is closer to the relaxed In(1-x)Ga(x)As shell. Microphotoluminescence measurements of the nanowires show emission in the infrared regime, which makes them suitable for applications in optical communication.
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Affiliation(s)
- Magnus Heurlin
- †The Nanometer Structure Consortium, Department of Physics, Lund University, Box 118, 221 00 Lund, Sweden
| | - Tomaš Stankevič
- ‡Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Simas Mickevičius
- ‡Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Sofie Yngman
- †The Nanometer Structure Consortium, Department of Physics, Lund University, Box 118, 221 00 Lund, Sweden
| | - David Lindgren
- †The Nanometer Structure Consortium, Department of Physics, Lund University, Box 118, 221 00 Lund, Sweden
| | - Anders Mikkelsen
- †The Nanometer Structure Consortium, Department of Physics, Lund University, Box 118, 221 00 Lund, Sweden
| | - Robert Feidenhans'l
- ‡Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Magnus T Borgström
- †The Nanometer Structure Consortium, Department of Physics, Lund University, Box 118, 221 00 Lund, Sweden
| | - Lars Samuelson
- †The Nanometer Structure Consortium, Department of Physics, Lund University, Box 118, 221 00 Lund, Sweden
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Stankevič T, Mickevičius S, Schou Nielsen M, Kryliouk O, Ciechonski R, Vescovi G, Bi Z, Mikkelsen A, Samuelson L, Gundlach C, Feidenhans'l R. Measurement of strain in InGaN/GaN nanowires and nanopyramids. J Appl Crystallogr 2015. [DOI: 10.1107/s1600576715000965] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
Abstract
The growth and optoelectronic properties of core–shell nanostructures are influenced by the strain induced by the lattice mismatch between core and shell. In contrast with planar films, nanostructures contain multiple facets that act as independent substrates for shell growth, which enables different relaxation mechanisms. In this study, X-ray diffraction data are presented that show that InαGa1−αN shells grown on GaN cores are strained along each of the facets independently. Reciprocal space maps reveal multiple Bragg peaks, corresponding to different parts of the shell being strained along the individual facet planes. The strained lattice constants were found from the positions of the Bragg peaks. Vegard's law and Hooke's law for an anisotropic medium were applied in order to find the composition and strain in the InGaN shells. A range of nanowire samples with different InGaN shell thicknesses were measured and it is concluded that, with an In concentration of around 30%, major strain relaxation takes place when the thickness reaches 23 nm. InGaN shells of 6 and 9 nm thickness remain nearly fully strained biaxially along each of the \{10{\overline 1}0\} facets of the nanowires and the \{10{\overline 1}1\} facets of the nanopyramids.
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Stankevič T, Medišauskas L, Stankevič V, Balevičius S, Żurauskienė N, Liebfried O, Schneider M. Pulsed magnetic field measurement system based on colossal magnetoresistance-B-scalar sensors for railgun investigation. Rev Sci Instrum 2014; 85:044704. [PMID: 24784635 DOI: 10.1063/1.4870280] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A high pulsed magnetic field measurement system based on the use of CMR-B-scalar sensors was developed for the investigations of the electrodynamic processes in electromagnetic launchers. The system consists of four independent modules (channels) which are controlled by a personal computer. Each channel is equipped with a CMR-B-scalar sensor connected to the measurement device-B-scalar meter. The system is able to measure the magnitude of pulsed magnetic fields from 0.3 T to 20 T in the range from DC up to 20 kHz independently of the magnetic field direction. The measurement equipment circuit is electrically separated from the ground and shielded against low and high frequency electromagnetic noise. The B-scalar meters can be operated in the presence of ambient pulsed magnetic fields with amplitudes up to 0.2 T and frequencies higher than 1 kHz. The recorded signals can be transmitted to a personal computer in a distance of 25 m by means of a fiber optic link. The system was tested using the electromagnetic railgun RAFIRA installed at the French-German Research Institute of Saint-Louis, France.
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Affiliation(s)
- T Stankevič
- Center for Physical Sciences and Technology, Semiconductor Physics Institute, A. Goštauto Str. 11, LT-01108 Vilnius, Lithuania
| | - L Medišauskas
- Center for Physical Sciences and Technology, Semiconductor Physics Institute, A. Goštauto Str. 11, LT-01108 Vilnius, Lithuania
| | - V Stankevič
- Center for Physical Sciences and Technology, Semiconductor Physics Institute, A. Goštauto Str. 11, LT-01108 Vilnius, Lithuania
| | - S Balevičius
- Center for Physical Sciences and Technology, Semiconductor Physics Institute, A. Goštauto Str. 11, LT-01108 Vilnius, Lithuania
| | - N Żurauskienė
- Center for Physical Sciences and Technology, Semiconductor Physics Institute, A. Goštauto Str. 11, LT-01108 Vilnius, Lithuania
| | - O Liebfried
- French-German Research Institute of Saint-Louis (ISL), 5, rue Général Cassagnou, F-68301 Saint-Louis, France
| | - M Schneider
- French-German Research Institute of Saint-Louis (ISL), 5, rue Général Cassagnou, F-68301 Saint-Louis, France
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