We study the structure, magnetization, electrical transport properties and heat capacity of the pyrochlore iridates A2Ir2O7（A=Y, Eu, Bi）. It is found that magnetic frustration and long-range magnetic order coexist i...We study the structure, magnetization, electrical transport properties and heat capacity of the pyrochlore iridates A2Ir2O7（A=Y, Eu, Bi）. It is found that magnetic frustration and long-range magnetic order coexist in Y2Ir2O7 and Eu2Ir2O7, while Bi2Ir2O7 shows magnetic frustration or short-range magnetic order without long-range magnetic order. The former two compounds show insulating behavior. However, the latter one shows metallic behavior. The variations of the radius of A-site ion affect the conduction bandwidth, correlation and Ir-Ir exchange energy, which in turn determine transport properties and magnetic properties. We also find that the antiferromagnetic ordering of pyrochlore iridates is weakly frustrated. The all-in/all-out type of anisotropy based on spin-orbit coupling plays a key role in releasing the frustration.展开更多
基金Supported by the National Natural Science Foundation of China(11604071)the Natural Science Foundation of the Education Department of Anhui Province(KJ2016SD49)the Natural Science Foundation of Hefei University(16ZR06ZDB,15RC13,14KY15ZR,2016dtr02)
文摘We study the structure, magnetization, electrical transport properties and heat capacity of the pyrochlore iridates A2Ir2O7（A=Y, Eu, Bi）. It is found that magnetic frustration and long-range magnetic order coexist in Y2Ir2O7 and Eu2Ir2O7, while Bi2Ir2O7 shows magnetic frustration or short-range magnetic order without long-range magnetic order. The former two compounds show insulating behavior. However, the latter one shows metallic behavior. The variations of the radius of A-site ion affect the conduction bandwidth, correlation and Ir-Ir exchange energy, which in turn determine transport properties and magnetic properties. We also find that the antiferromagnetic ordering of pyrochlore iridates is weakly frustrated. The all-in/all-out type of anisotropy based on spin-orbit coupling plays a key role in releasing the frustration.
