Crystal structure of novel hydrides in a Mg-Ni-H system prepared under an ultra high pressure
Crystal structure of novel hydrides in a Mg-Ni-H system prepared under an ultra high pressure
复制标题
超高压制备的Mg-Ni-H体系中新型氢化物的晶体结构
DOI：
10.1016/s0925-8388(01)01577-8
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发表时间：
2002
影响因子：
6.2
通讯作者：
M. Okada
中科院分区：
文献类型：
--
作者：
H. Takamura;H. Kakuta;A. Kamegawa;M. Okada
用X射线粉末衍射和透射电子显微镜研究了Mg-Ni-H体系中新化合物的晶体结构。使用一个双砧型装置来制备样品。在1073 K和5 GPa的压力下反应2 h合成了化学组成为MgH 2 -60 at% Ni的氢化物。从TGA分析，发现新的氢化物为Mg2Ni3H3.4。正交晶系和单斜晶系的原始细胞被认为是新的氢化物的可能的对称性。新氢化物的X射线衍射和电子衍射图均为正交晶系结构，a=0.8859（4），B=1.3740（5），c=0.4694（2）nm。此外，通过透射电子显微镜观察到氢化物分解成Mg 2Ni。
The crystal structure of novel hydrides in the Mg–Ni–H system has been studied using a powder X-ray diffraction and transmission electron microscopy. A cubic-anvil-type apparatus was utilized to prepare samples. The new hydride with a chemical composition of around MgH2–60 at% Ni was synthesized at 1073 K for 2 h under a pressure as high as 5 GPa. From TGA analysis, the new hydride was found to be Mg2Ni3H3.4. Orthorhombic and monoclinic crystal systems with a primitive cell were proposed as possible symmetries of the new hydride. X-ray and electron diffraction patterns of the new hydride were indexed in an orthorhombic structure with a=0.8859(4), b=1.3740(5), c=0.4694(2) nm. Moreover, decomposition of the hydride into Mg2Ni was observed by the transmission electron microscopy.