Preparation, properties and crystal structures of the thorium chromium borides ThCrB4 and ThCr2B6; structure refinements of CeCr2B6, ThB4 and ThB6
作者:Thomas Konrad、Wolfgang Jeitschko、Martin E. Danebrock、Christoph B.H. Evers
DOI:10.1016/0925-8388(95)01993-6
日期:1996.2
and their crystal structures were determined from single-crystal X-ray data. ThCrB4 has a YCrB4-type structure: Pbam, a = 605.8(1) pm, b = 1171.2(2) pm, c = 364.0(1) pm, R = 0.024 for 714 structure factors and 26 variable parameters. ThCr2B6 is isotypic with CeCr2B6: Immm, a = 315.8(1) pm, b = 659.1(1) pm, c = 836.4(2) pm, R = 0.030 (415 F values, 14 variables). The structures of the borides CeCr2B6
摘要 通过元素组分的电弧熔炼制备了新型聚硼化物ThCrB4和ThCr2B6,并利用单晶X射线数据确定了它们的晶体结构。ThCrB4 具有 YCrB4 型结构:Pbam,a = 605.8(1) pm,b = 1171.2(2) pm,c = 364.0(1) pm,对于 714 个结构因子和 26 个可变参数,R = 0.024。ThCr2B6 与 CeCr2B6 同型:Immm,a = 315.8(1) pm,b = 659.1(1) pm,c = 836.4(2) pm,R = 0.030(415 F 值,14 个变量)。硼化物 CeCr2B6、ThB4 和 ThB6 的结构是从单晶 X 射线数据中提炼出来的。ThB4 和 ThB6 的 B6 八面体之间的 BB 键比八面体内的键短得多。ThCrB4、ThCr2B6 和 CeCr2B6 是金属导体,泡利顺磁性。