Nanowire crystals of tantalum nitride grown in ammonium halide fluxes at high pressures
Nanowire crystals of tantalum nitride grown in ammonium halide fluxes at high pressures
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DOI：
10.1063/1.5140856
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发表时间：
2020-03
影响因子：
4
通讯作者：
N. A. Gaida;Takuya Sasaki;Zheng Liu;K. Niwa;Masaki Hirozawa;T. Ohsuna;M. Hasegawa
中科院分区：
文献类型：
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作者：
N. A. Gaida;Takuya Sasaki;Zheng Liu;K. Niwa;Masaki Hirozawa;T. Ohsuna;M. Hasegawa
氮化钽相的纳米线晶体是由ε-氮化钽和卤化铵前体在超过几千兆帕的高压下生长而成的。同步辐射X射线衍射和透射电子显微镜（TEM）观察表明，它们以未报道的六方结构结晶，晶格参数为a = 3.050(1) A和c = 2.909(2) A。一维生长方向沿晶体学[001]方向。扫描 TEM-EDX 元素分析表明纳米线晶体由钽和氮以及少量氧组成。熔融卤化铵与超临界氨的存在在高压和高温下充当反应助熔剂，在纳米线晶体生长中发挥了重要作用。对几种单晶纳米线进行的拉曼光谱表明了金属特性，超导量子干涉装置磁力测量测量的磁化强度的温度依赖性表明超导转变约为 6.2 K。压缩行为的分析揭示了不可压缩的性质，体积模量确定为 363(6) GPa。氮化钽相的纳米线晶体是由 ε-氮化钽和卤化铵前体在高温下生长的。压力超过数吉帕斯卡。同步辐射X射线衍射和透射电子显微镜（TEM）观察表明，它们以未报道的六方结构结晶，晶格参数为a = 3.050(1) A和c = 2.909(2) A。一维生长方向沿晶体学[001]方向。扫描 TEM-EDX 元素分析表明纳米线晶体由钽和氮以及少量氧组成。熔融卤化铵与超临界氨的存在在高压和高温下充当反应助熔剂，在纳米线晶体生长中发挥了重要作用。对几种单晶纳米线进行的拉曼光谱表明金属特性，以及超导量子干涉仪测量的磁化强度的温度依赖性......
Nanowire crystals of a tantalum nitride phase have been grown from epsilon-tantalum nitride and ammonium halide precursors at high pressures exceeding several gigapascals. Synchrotron x-ray diffraction and Transmission Electron Microscopy (TEM) observations revealed that they had crystallized in an unreported hexagonal structure with lattice parameters of a = 3.050(1) A and c = 2.909(2) A. The one-dimensional growth orientation was along the crystallographic [001] direction. Scanning TEM–EDX elemental analyses showed that the nanowire crystals were composed of tantalum and nitrogen with small amounts of oxygen. The presence of the melted ammonium halides combined with supercritical ammonia acting as a reactive flux at high pressure and temperature played a significant role in the nanowire crystal growth. Raman spectroscopy performed on several single crystal nanowires pointed toward metallic properties, and the temperature dependence of the magnetization measured by Superconducting Quantum Interference Device magnetometry suggested a superconducting transition about 6.2 K. The analysis of the compression behavior revealed an incompressible nature, and the bulk modulus was determined to be 363(6) GPa.Nanowire crystals of a tantalum nitride phase have been grown from epsilon-tantalum nitride and ammonium halide precursors at high pressures exceeding several gigapascals. Synchrotron x-ray diffraction and Transmission Electron Microscopy (TEM) observations revealed that they had crystallized in an unreported hexagonal structure with lattice parameters of a = 3.050(1) A and c = 2.909(2) A. The one-dimensional growth orientation was along the crystallographic [001] direction. Scanning TEM–EDX elemental analyses showed that the nanowire crystals were composed of tantalum and nitrogen with small amounts of oxygen. The presence of the melted ammonium halides combined with supercritical ammonia acting as a reactive flux at high pressure and temperature played a significant role in the nanowire crystal growth. Raman spectroscopy performed on several single crystal nanowires pointed toward metallic properties, and the temperature dependence of the magnetization measured by Superconducting Quantum Interference De...