Suchergebnisse

Mg3Sb2-based thermoelectric materials attract attention for applications near room temperature. Here, Mg-Bi films were synthesized using magnetron sputtering at deposition temperatures from room temperature to 400 °C. Single-phase Mg3Bi2 thin films were grown on c-plane-oriented sapphire and Si(100) substrates at a low deposition temperature of 200 °C. The Mg3Bi2 films grew epitaxially on c-sapphire and fiber-textured on Si(100). The orientation relationships for the Mg3Bi2 film with respect to the c-sapphire substrate are (0001) Mg3Bi2‖(0001) Al2O3 and [112⎯⎯2¯0] Mg3Bi2‖[112⎯⎯2¯0] Al2O3. The observed epitaxy is consistent with the relatively high work of separation, calculated by the density functional theory, of 6.92 J m−2 for the Mg3Bi2 (0001)/Al2O3 (0001) interface. Mg3Bi2 films exhibited an in-plane electrical resistivity of 34 μΩ m and a Seebeck coefficient of +82.5 μV K−1, yielding a thermoelectric power factor of 200 μW m−1 K−2 near room temperature.This work was supported financially by the Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linköping University (Faculty Grant SFO-Mat-LiU No. 2009 00971), the Knut and Alice Wallenberg Foundation through the Wallenberg Academy Fellows program (No. KAW-2020.0196), the Swedish Research Council (VR) under Project Nos. 2016-03365 and 2021-03826, the National Key Research and Development Program of China under Grant No. 2018YFB0703600, the National Natural Science Foundation of China under Grant No. 51872133, the Guangdong Innovative and Entrepreneurial Research Team Program under Grant No. 2016ZT06G587, and the Tencent Foundation through the XPLORER PRIZE, Guangdong Provincial Key Laboratory Program (No. 2021B1212040001) from the Department of Science and Technology of Guangdong Province. The computations were performed on resources provided by the Swedish National Infrastructure for Computing (SNIC) at National Supercomputer Centre (NSC) partially funded by the Swedish Research Council through Grant Agreement No. 2018-05973.

Mg3Sb2-based thermoelectric materials attract attention for applications near room temperature. Here, Mg-Bi films were synthesized using magnetron sputtering at deposition temperatures from room temperature to 400 & DEG;C. Single-phase Mg3Bi2 thin films were grown on c-plane-oriented sapphire and Si(100) substrates at a low deposition temperature of 200 & DEG;C. The Mg3Bi2 films grew epitaxially on c-sapphire and fiber-textured on Si(100). The orientation relationships for the Mg3Bi2 film with respect to the c-sapphire substrate are (0001) Mg3Bi2||(0001) Al2O3 and [11 2 over bar 0] Mg3Bi2||[11 2 over bar 0] Al2O3. The observed epitaxy is consistent with the relatively high work of separation, calculated by the density functional theory, of 6.92 J m(-2) for the Mg3Bi2 (0001)/Al2O3 (0001) interface. Mg3Bi2 films exhibited an in-plane electrical resistivity of 34 mu omega m and a Seebeck coefficient of +82.5 mu V K-1, yielding a thermoelectric power factor of 200 mu W m(-1) K-2 near room temperature. ; Funding Agencies|Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009 00971]; Knut and Alice Wallenberg Foundation through the Wallenberg Academy Fellows program [KAW-2020.0196]; Swedish Research Council (VR)Swedish Research Council [2016-03365, 2021-03826, 2018-05973]; National Key Research and Development Program of China [2018YFB0703600]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [51872133]; Guangdong Innovative and Entrepreneurial Research Team Program [2016ZT06G587]; Tencent Foundation through XPLORER PRIZE [2021B1212040001]

Multicomponent TixNbCrAl nitride films were deposited on Si(100) substrates by reactive direct current magnetron sputtering (dcMS) and high power impulse magnetron sputtering (HiPIMS) in the absence of substrate heating and bias. Three single Ti, Nb, and Cr50Al50 targets were either driven by three de or three HiPIMS power supplies. The Ti content in the films was varied by tuning the power applied to the Ti target. The composition was determined by ion beam analysis. The nitrogen content is nearly stoichiometric (48-50 at.%) in the HiPIMS series, while the dcMS are understoichiometric (39-45 at.%). The crystal structure, stress and density of the studied film were investigated by X-ray techniques and the microstructure was examined by scanning electron microscopy. All the Ti-containing films for both series exhibit an fcc NaCl-type phase structure. In particular, the dcMS series shows a (111) preferred orientation, resulting in a faceted surface morphology compared to a dense and smooth microstructure of the HiPIMS films. The compressive stress of the HiPIMS series (> 2.0 GPa) is significantly larger than the values of the dcMS series (<0.5 GPa). Nanoindentation measurements show a maximum hardness of 29.9 GPa and Youngs modulus of 304 GPa were obtained in the HiPIMS series. The results may promote HiPIMS techniques for the synthesis of complex multicomponent films for the application aspect to protective and hard coatings. ; Funding Agencies|VINNOVA Competence Centre FunMat-II [2016-05156]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009 00971]; M - ERA. net (project MC2) [2013-02355]; Knut and Alice Wallenberg FoundationKnut & Alice Wallenberg Foundation [2020.0196, KAW 2015.0043]; Electron Microscopy Laboratory at Linkoping University; Swedish Research CouncilSwedish Research CouncilEuropean Commission [VR 2018-04139]; Swedish Research Council VR-RFISwedish Research Council [2019-00191]; Swedish Foundation for Strategic ResearchSwedish Foundation for Strategic Research [RIF14-0053]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [51805102]; Guizhou Provincial Natural Science Foundation [[2020]1Y228]; China Scholarship Council (CSC)China Scholarship Council