High-pressure synthesis of novel hydride in Mg–Ni–H and Mg–Ni–Cu–H systems
High-pressure synthesis of novel hydride in Mg–Ni–H and Mg–Ni–Cu–H systems
复制标题
Mg-Ni-H和Mg-Ni-Cu-H体系中新型氢化物的高压合成
DOI：
10.1016/j.jallcom.2007.04.221
复制
发表时间：
2007
影响因子：
6.2
通讯作者：
M. Okada
中科院分区：
文献类型：
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作者：
R. Kataoka;Y. Goto;A. Kamegawa;H. Takamura;M. Okada
采用高压顶砧法在Mg-Ni-H和Mg-Ni-Cu-H体系中合成了新型的Mg-Ni-Cu-H化合物。研究了其晶体结构和热稳定性。在973 K、2GPa以上的压力下反应2 h合成了MgNi_2Hy_3氢化物。该氢化物可以由每种起始原料合成，例如MgNi 2（C 36）和MgH 2-xmol% Ni（x=65-70）的混合物。通过熔融分析，MgH 2 - 67 at.%样品的氢含量在973 K、5GPa条件下，以氢源反应2 h制备的Ni的质量分数为2.23mass%，化学式为MgNi2H3.2。该氢化物具有体心四面体结构（空间群I4/mmm，No.139），晶格常数a=0.327（3）nm，c=0.878（9）nm。此外，氢化物的晶体结构随Ni含量的变化而发生畸变，表现为C面心斜方晶系（空间群Pmmm，No.47），晶格常数a=0.460（1）nm，B=0.468（1）nm，c=0.893（1）nm。在Mg-Ni-Cu-H体系中，研究了Mg（Ni 1-xCux）2 Hy（x=0.05，0.10，0.15，0.20）的晶体结构和热稳定性。在5GPa压力下，以973 K氢源反应8h制备的Mg（Ni 0. 95 Cu 0. 05）2样品在446 K下发生脱氢反应，比MgNi 2 H 3. 2的脱氢温度低15 K。此外，在5GPa压力下，以973 K氢源反应2 h制备的Mg（Ni0.95Cu0.05）2在409 K发生了分解，氢反应不充分。
Novel hydrides were synthesized in Mg–Ni–H and Mg–Ni–Cu–H systems by high-pressure technique using a cubic-anvil-type apparatus. Crystal structure and thermal stability of the hydrides were studied. The novel hydride with a composition of MgNi2Hywas synthesized at 973K for 2h under the pressure of over 2GPa. This hydride could be synthesized from each starting material, such as MgNi2(C36) and mixture of MgH2–xmol% Ni (x=65–70). From fusion analysis, hydrogen content of the sample of MgH2–67at.% Ni prepared with hydrogen source at 973K for 2h under 5GPa was estimated to be 2.23mass% and chemical formula was corresponding to be MgNi2H3.2. The novel hydride was found to exhibit the body-centered tetragonal structure (space group I4/mmm, No. 139) with lattice parameters of a=0.327(3)nm, c=0.878(9)nm. Moreover, crystal structure of novel hydride was distorted with varying Ni content, then it was found to exhibit C-faced based-centered orthorhombic structure (space group Pmmm, No. 47) with lattice parameters of a=0.460(1)nm, b=0.468(1)nm, c=0.893(1)nm. In Mg–Ni–Cu–H system, crystal structure and thermal stability of Mg(Ni1−xCux)2Hy(x=0.05, 0.10, 0.15, 0.20) were investigated. The sample of Mg(Ni0.95Cu0.05)2prepared with hydrogen source at 973K for 8h under 5GPa was dehydrogenated at 446K, which is 15K lower than that of MgNi2H3.2. Moreover, Mg(Ni0.95Cu0.05)2prepared with hydrogen source at 973K for 2h under 5GPa,which did not react hydrogen sufficiently, was decomposed at 409K.
合成压力对 Mg-M 体系 (M=Mn,Y) 中氢化物相的影响
DOI：
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发表时间：
2003
期刊：
Science and Technology of Advanced Materials 4
影响因子：
--
作者：
Y.Goto;H.Kakuta;A.Kamegawa;H.Takamura;M.Okada
通讯作者：
M.Okada