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- Polley, Craig, et al.
(författare)
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Observation of topological crystalline insulator surface states on (111)-oriented Pb1-xSnxSe films
- 2014
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 89:7, s. 075317-
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Tidskriftsartikel (refereegranskat)abstract
- We present angle-resolved photoemission spectroscopy measurements of the surface states on in-situ grown (111) oriented films of Pb1-xSnxSe, a three-dimensional topological crystalline insulator. We observe surface states with Dirac-like dispersion at (Gamma) over bar and (M) over bar in the surface Brillouin zone, supporting recent theoretical predictions for this family of materials. We study the parallel dispersion isotropy and Dirac-point binding energy of the surface states, and perform tight-binding calculations to support our findings. The relative simplicity of the growth technique is encouraging, and suggests a clear path for future investigations into the role of strain, vicinality, and alternative surface orientations in (Pb,Sn)Se solid solutions.
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- Khranovskyy, V., et al.
(författare)
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Improvement of ZnO thin film properties by application of ZnO buffer layers
- 2007
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Ingår i: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248 .- 1873-5002. ; 308:1, s. 93-98
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Tidskriftsartikel (refereegranskat)abstract
- The effect of ZnO buffer layers prepared at different temperatures on the structural, optical and morphological properties of the ZnO main layer is reported. ZnO thin films (comprising a buffer and a main layer) were deposited on (0 0 0 1) c-sapphire substrates by PEMOCVD. Two-step growth regimes were applied to realize a homoepitaxial growth on ZnO buffers: low-temperature ZnO buffer layer deposited at Ts=300 °C and the main layer at Ts=500 °C, high-temperature ZnO buffer layer deposited at Ts=500 °C and the main layer at Ts=300 °C. For comparison, a sample grown at high-temperature Ts=500 °C by one-step procedure was used. The low-temperature buffer layer has shown the most beneficial effect on the structural and morphological properties, as expressed by the narrowing of the (0 0 2) diffraction peak (FWHM=0.07°) and crystallite size enlargement. However, the surface roughness of this sample is higher then that of the sample grown by one-step procedure and this needs further considerations. The photoluminescence results seem to support a conclusion that the application of a low-temperature buffer layer among the studied temperature regimes is the most advantageous. © 2007 Elsevier B.V. All rights reserved.
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- Paszkowicz, Wojciech, et al.
(författare)
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Silver behenate under high pressure: A powder diffraction study
- 2009
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Ingår i: Radiation Physics and Chemistry. - : Elsevier BV. - 0969-806X. ; 78, s. 105-108
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Konferensbidrag (refereegranskat)abstract
- Silver behenate, a salt of the behenic acid, known mostly for its applications in photothermographic imaging and use as a diffraction reference material, was studied by X-ray diffraction under pressures up to 11.4 GPa. Diffraction patterns were collected using a diamond anvil cell and synchrotron radiation at the 1711 beamline (MAXlab, Lund). The variation of the d spacing with pressure is determined and the potential usefulness of this dependence for pressure calibration is discussed. (C) 2009 Elsevier Ltd. All rights reserved.
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