过渡金属铋化物BaAg_(2-δ)Bi_2单晶的制备和物理性质

Single Crystal Growth and Physical Properties of Layered Transitional Metal Bismuthide BaAg_(2-δ)Bi_2

采用自助熔方法制备了高质量的层状过渡金属铋化物BaAg_(2-δ)Bi_2单晶样品,通过多种实验手段综合研究了该单晶样品的晶体结构、化学成分、电学和磁学性质。结果表明:化合物BaAg_(2-δ)Bi_2是一种层状过渡金属化合物,具有AgBi_4和BiAg_4四面体层,这与铁基超导体中只有FeAs_4/FeSe_4四面体层明显不同。电阻率和磁化率随温度变化的曲线显示,在1.8~300K温度区间BaAg_(2-δ)Bi_2表现出很好的金属性和顺磁性,其顺磁性主要来源于传导电子的贡献。

High quality single crystal sample of layered transitional metal bismuthide BaAg2-δBi2 was prepared by self-fluxing method.The crystal structure,chemical composition,electrical and magnetic properties of high quality single crystal sample were systematically studied by many kinds of experimental methods.The experiment results indicate that the compound BaAg2-δBi2 is a layered transitional metal compounds with AgBi4 and BiAg4 tetrahedral layers,which is different from that there is only one kind of FeAs4/FeSe4 tetrahedral layers in iron-based superconductor.The variation of resistivity and magnetic susceptibility as a function of temperature shows that BaAg2-δBi2 presents a good metal behavior and paramagnetism in the temperature ranges of 1.8 — 300 K,and the paramagnetism mainly originate from conduction electrons.