Mg_3MNi_2(M=Ti,Al)的晶体结构  

THE CRTSTAL STRUCTURE OF NEW HYDROGEN STORAGE Mg_3MNi_2 (M=Al, Ti) ALLOYS

作　　者：吕光烈[1] 陈林深[1] 胡秀荣[1] 王连邦[2] 袁华堂[2] 

机构地区：[1]浙江大学中心实验室,杭州310028 [2]南开大学新能源材料化学所,天津300071

出　　处：《金属学报》2001年第5期459-462,共4页Acta Metallurgica Sinica

基　　金：国家自然科学基金59671016;59781001;浙江省分析测试基金资助项目

摘　　要：Ａｌ和Ｔｉ对Ｍｇ２Ｎｉ结构中部分Ｍｇ的取代，得到与Ｍｇ２Ｎｉ晶体结构不同的新型合金．多晶Ｘ射线结构分析表明，其化学式为Ｍｇ３ＭＮｉ２（Ｍ＝Ｔｉ，Ａｌ），立方晶系，空间群Ｆｄ３ｍ， Ｚ＝１６，４８个Ｍｇ坐落在４８（ｆ），１６个 Ｍ（Ｍ＝Ａｌ， Ｔｉ）坐落在１６（ｄ）位，３２个Ｎｉ坐落在３２（ｅ）位，Ｍｇ３ＡｌＮｉ２的晶胞参数ａ＝１．１５４７４（２）ｎｍ， Ｍｇ３ＴｉＮｉ２的ａ＝１．１６１７８（２）ｎｍ．与Ｍｇ２Ｎｉ相比，Ｍｇ３ＭＮｉ２合金的晶体密度更大，Ｍｇ－Ｎｉ键长更长，吸放氢温度降低，循环寿命延长．A new phase different to Mg2Ni was obtained when Mg component in Mg2Ni was partially replaced by Al or Ti. X-ray powder diffraction structure analysis showed that the new phase is of cubic system, S. G. Fd3m, (No.227), the chemical formula Mg3MNi2 (M=Al, Ti). Z=16, sixteen molecules per unit cell, cell parameter a=1.15474(2) nm for Mg3AlNi2 and a=1.16178(2) nm for Mg3TiNi2, 48 atoms of Mg are located on 48(f) sites, 16 atoms of M (Ti, Al) on 16(d) and 32 atoms of Ni on 32(e). Compared with Mg2Ni, Mg3AlNi2 has bigger density and longer Mg-Ni bond length. Meanwhile, the hydriding/dehydriding temperature is lower and the electrochemical cycle life is longer.

关 键 词：贮氢合金 XRD结构分析 Mg2MNi2(M=Al Ti) 

分 类 号：TG139.7[一般工业技术—材料科学与工程] TG113.12[金属学及工艺—合金]