USb2单晶的生长及磁性和输运性质研究

Crystal Growth, Magnetic and transport properties of USb2

摘要:

采用Sb自助熔剂法成功生长高质量的USb₂单晶，并研究了磁化率、电阻、磁阻和比热等性质。研究表明，中等关联强度的USb₂中的5f电子具有巡游和局域双重特征。USb₂中的5f电子在260 K附近开始发生相干，203 K由顺磁态转变为反铁磁态，进行费米面的重构。在113 K以下局域的5f电子与传导电子发生第一次杂化使费米面附近电子结构发生变化。在54 K以下通过第二次杂化使得费米面附近形成了杂化能隙。在更低温度下晶体场效应对物理性质也产生了一定的影响。

Abstract:

High-quality single crystals of USb₂ were grown by the Sb self-flux method. The magnetic susceptibility, resistivity, magnetoresistance and specific heat were measured. The results indicate that, the 5f electrons in USb₂ with moderately correlated electron system exhibit dual characteristics of both localized and itinerant behaviors. The 5f electrons of USb₂ begin to coherent about 260 K. USb₂ transforms from paramagnetic into antiferromagnetic state at 203 K and the reconstruction of the Fermi surface occurs. The electronic structure near Fermi surface is further changed through the first hybridization between the localized 5f electrons and the conduction electrons below 113 K. The second hybridization leads to open one energy gap near the Fermi surface below 54 K. The crystal field effects have an important impact on physical properties at lower temperatures.