Synthesis of New Hydrides with Cubic Structures in Mg-Ca-Ni Systems by Using High Pressure
Synthesis of New Hydrides with Cubic Structures in Mg-Ca-Ni Systems by Using High Pressure
复制标题
Mg-Ca-Ni体系中高压合成立方结构新型氢化物
DOI：
10.2320/matertrans.42.1850
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发表时间：
2001
影响因子：
1.2
通讯作者：
M. Okada
中科院分区：
文献类型：
--
作者：
Y. Goto;H. Kakuta;A. Kamegawa;H. Takamura;M. Okada
研究了Ca-Mg-Ni-H体系在5GPa高压下合成的新型稀土氧化物的物相和热稳定性。高压合成在1073 K-1223 K和5 GPa下进行2 h。在x = 0- 0.4范围内，发现一系列（Ca 1-xMgx）2NiH δ形成固溶体.该氢化物在646 K左右分解，与Mg含量无关。在CaH_2-X % MgH_2体系中，在X = 50-67范围内，得到了BCC结构的CaH_2。随着Mg含量的增加，BCC相的晶格常数从0.4032（9）nm（X = 50）减小到0.3988（3）nm（X = 67）。随着Mg含量的增加，即随着BCC相晶格常数的减小，BCC相的分解温度从650 K（X = 50）升高到673 K（X = 67）。
Phases and thermal stability of new hydrides synthesized by using under a high pressure of 5 GPa in Ca-Mg-Ni-H systems were studied. The high-pressure synthesis was carried out at 1073 K-1223 K for 2 h under 5 GPa by using an anvil-type apparatus. A series of (Ca 1-x Mg x ) 2 NiH δ was found to form solid solution in the range of x = 0-0.4. This hydride decomposed around 646K regardless of Mg content. In CaH2-X%MgH2 systems, hydrides with BCC structure were obtained in the range of X = 50-67. Lattice constant of the BCC phase decreased from 0.4032(9) nm (X = 50) to 0.3988(3) nm (X = 67) with increasing Mg content. The decomposed temperature of the BCC phase increased from 650 K (X = 50) to 673 K (X = 67) with increasing Mg content, in other words, with decreasing the lattice constant of BCC phase.