A5059485081- Heusler alloys: electronic and magnetic properties
- Magnetic properties of thin films
- Semiconductor materials and interfaces
- Topological Materials and Phenomena
- MXene and MAX Phase Materials
- Magnetic and transport properties of perovskites and related materials
- Graphene research and applications
- Boron and Carbon Nanomaterials Research
- 2D Materials and Applications
- Magnetic Properties and Synthesis of Ferrites
- Diamond and Carbon-based Materials Research
- Advanced Thermoelectric Materials and Devices
- Photorefractive and Nonlinear Optics
- Intermetallics and Advanced Alloy Properties
- Metal and Thin Film Mechanics
- Scientific Research and Discoveries
- Chalcogenide Semiconductor Thin Films
- Multiferroics and related materials
- Advanced Condensed Matter Physics
- Ferroelectric and Piezoelectric Materials
- Ferroelectric and Negative Capacitance Devices
- Electronic and Structural Properties of Oxides
- Inorganic Chemistry and Materials
- Advanced Chemical Physics Studies
Austrian Academy of Sciences
2020-2021
University of York
2016-2021
Erich Schmid Institute of Materials Science
2020-2021
Montanuniversität Leoben
2019
Osaka University
2016
University of Warwick
2016
Spintronics Research Network of Japan
2016
Defects significantly affect the mechanical properties of materials. However, quantitatively correlating point defects with property could be a challenge. In this study, we explore defect effects on structure and magnetron sputtered TiN nanocrystalline films (synthesized using different negative bias potential) via combination analytical techniques density functional theory (DFT) calculations. We gain insights into structural evolution at length scales. It is found that nanocrystal...
We present a structural and density functional theory study of FexCu1−xSe within the three-dimensional topological insulator Bi2Te3. The inclusions are single-crystalline epitaxially oriented with respect to Bi2Te3 thin film. Aberration-corrected scanning transmission electron microscopy energy loss spectroscopy show an atomically sharp FeICu1−xSe/Bi2Te3 interface. FexCu1−xSe/Bi2Te3 interface is determined by Se–Te bonds no misfit dislocations observed, despite different lattice symmetries...
Abstract Halfmetal-semiconductor interfaces are crucial for hybrid spintronic devices. Atomically sharp with high spin polarisation required efficient injection. In this work we show that thin film of half-metallic full Heusler alloy Co 2 FeSi 0.5 Al uniform thickness and B2 ordering can form structurally abrupt interface Ge(111). Atomic resolution energy dispersive X-ray spectroscopy reveals there is a small outdiffusion Ge into specific atomic planes the film, limited to very narrow...
We show direct evidence for the impact of Heusler/semiconductor interfaces atomic structure on spin transport signals in semiconductor-based lateral spin-valve (LSV) devices. Based scale Z-contrast scanning transmission electron microscopy and energy dispersive x-ray spectroscopy we that order/disorder ${\mathrm{Co}}_{2}{\mathrm{FeAl}}_{0.5}{\mathrm{Si}}_{0.5}$ (CFAS)/$n$-Ge LSV devices is critical injection Ge. By conducting a postannealing devices, find 90% decrease signal while there no...
We present a nanoscale structural and density functional study of the Mn doped 3D topological insulator Bi2Te3. X-ray absorption near edge structure shows that has valency nominally 2+. Extended x-ray fine spectroscopy in combination with electron energy loss (EELS) is substitutional dopant Bi Te also resides van der Waals gap between quintuple layers Combination aberration-corrected scanning transmission microscopy EELS substitution occurs film regions increased concentration....
We show that Co2FeAl0.5Si0.5 film deposited on Si(111) has a single crystal structure and twin related epitaxial relationship with the substrate. Sub-nanometer electron energy loss spectroscopy shows in narrow interface region there is mutual inter-diffusion dominated by Si Co. Atomic resolution aberration-corrected scanning transmission microscopy reveals B2 ordering. The lattice unaltered even at due to substitutional nature of intermixing. First-principles calculations performed using...
Abstract We present a study of the structure and chemical composition Cr-doped 3D topological insulator Bi 2 Se 3 . Single-crystalline thin films were grown by molecular beam epitaxy on Al O (0001), their structural properties determined an atomic level aberration-corrected scanning transmission electron microscopy energy loss spectroscopy. A regular quintuple layer stacking film is found, with exception first several layers in initial growth. The spectroscopy data gives direct evidence that...
Atomic resolution scanning transmission electron microscopy reveals the presence of an antiphase boundary in half-metallic Co2Fe(Al,Si) full Heusler alloy. By employing density functional theory calculations, we show that this defect leads to reversal sign spin-polarization vicinity defect. In addition, reduces strength exchange interactions, without changing ferromagnetic ordering across boundary. Atomistic spin calculations predict effect width magnetic domain wall compared bulk.
Segregation is a crucial phenomenon, which has to be considered in functional material design. processes perovskite oxides have been the subject of ongoing scientific interest, since they can lead modification properties and loss functionality. Many studies oxide thin films focused on segregation toward surface using variety surface-sensitive analysis techniques. In contrast, here we report Ca an in-plane compressively strained heterostructure interface Ca- Mn-codoped bismuth ferrite film....
By using first-principles calculations we show that the spin-polarization reverses its sign at atomically abrupt interfaces between half-metallic Co2(Fe,Mn)(Al,Si) and Si(1 1 1). This unfavourable spin-electronic configuration Fermi-level can be completely removed by introducing a Si-Co-Si monolayer interface. In addition, this interfacial shifts from valence band edge close to conduction of Si. We such layer is energetically favourable exist was further confirmed direct observations CoSi2...
Abstract The depth-resolved chemical structure and magnetic moment of <?CDATA $ \newcommand{\CFAS}{{\rm Co}_{2}{\rm FeAl}_{0.5}{\rm Si}_{0.5}} \CFAS$ ?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mstyle displaystyle="false"> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">C</mml:mi> mathvariant="normal">o</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> mathvariant="normal">F</mml:mi> mathvariant="normal">e</mml:mi> mathvariant="normal">A</mml:mi>...
We present a structural and density-functional theory study of the interface quasi-twin-free grown three-dimensional topological insulator ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$ on Ge(111). Aberration-corrected scanning transmission electron microscopy energy-loss spectroscopy in combination with first-principles calculations show that weak van der Waals adhesion between quintuple layer Ge can be overcome by forming an additional Te at their interface. The formation energy it to energetically...
Journal Article Atomic and electronic structure study of a Co 2 FeAl 0.5 Si half-metal thin film on Si(111) Get access Demie Kepaptsoglou, Kepaptsoglou SuperSTEM Laboratory, SciTech Daresbury Campus, United Kingdom Search for other works by this author on: Oxford Academic Google Scholar Barat Kuerbanjiang, Kuerbanjiang Department Physics, University York, Zlatko Nedelkoski, Nedelkoski Arsham Ghasemi, Ghasemi Shinya Yamada, Yamada Systems Innovation, Osaka University, Japan Kohei Hamaya,...
Engineering of the atomic structure hetero-interfaces enables tuning electronic properties heterostructure such as band alignment, Schottky barrier height, interface conductivity and magnetism.Hence it is aim continuous experimental theoretical research to control chemical intermixing arising due interdiffusion, well strain, which are main parameters that structural quality a given heterostructure.However, tailoring ferromagnet/semiconductor interfaces, crucial importance for spintronic...