USb_2单晶的生长、磁性和输运性质研究

Growth, Magnetic and Transport Properties of USb_2 Single Crystal

采用Sb自助熔剂法成功生长高质量的USb_2单晶,并研究了磁化率、电阻、磁阻和比热容等性质。研究表明,中等关联强度的USb_2中的5f电子具有巡游和局域双重特征。USb_2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。

High-quality single crystals of USb_2 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 USb_2 with a moderately correlated electron system exhibit dual characteristics of localized and itinerant behaviors. The 5f electrons of USb_2 begin to cohere around 260 K. USb_2 transforms from paramagnetic into antiferromagnetic 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 opens one energy gap near the Fermi surface below 54 K. The crystal field effects also influence physical properties at lower temperatures.