SmCo1-xFexAsO的多重磁性转变  

Multiple Magnetic Transitions in SmCo_(1-x)Fe_xAsO

作　　者：苏春燕[1] 陈永亮[1] 周大进[1] 王小峰[1] 李平原[1] 崔雅静[1] 赵勇[1,2] 

机构地区：[1]磁浮技术与磁浮列车教育部重点实验室,西南交通大学,超导与新能源研究开发中心,四川成都610031 [2]University of New South Wales,Sydney 2052,Australia

出　　处：《稀有金属材料与工程》2014年第10期2431-2434,共4页Rare Metal Materials and Engineering

基　　金：国家磁约束核聚变能研究专项(2011GB112001);国际合作项目(2013DFA51050);国家自然科学基金(11104224,11004162,51271155);高等学校博士学科点专项科研基金新教师类课题(20110184120029);四川省科技计划项目(2011JY0031,2011JY0130);中央高校基本科研业务费专项资金(SWJTU11BR063)

摘　　要：采用固相反应法,制备出一系列SmCo1-xFexAsO（x=0,0.05,0.1,0.2）多晶样品。XRD测试结果表明所有样品均为单相,且具有ZrCuSiAs型四方结构,随着掺杂量的增加,晶格参数a逐渐减小,c逐渐增加。磁性测量结果表明,低掺杂量样品在5~300 K之间先后经历了反铁磁-铁磁-顺磁的磁性转变,低场下的M-T曲线表现出明显的不可逆性,且随着掺杂量的增加,反铁磁转变温度降低,铁磁转变温度向高温方向移动,表明样品的反铁磁性逐渐被抑制,而铁磁性逐渐增强。M-H曲线表明,在反铁磁转变温度以下,掺杂量x〈0.2的样品,随着磁场的增加发生了由反铁磁到铁磁性的变磁性转变,且随着掺杂量的增加,在同一温度下的转变磁场变小。在掺杂量x=0.2时,当温度降低到5 K时仍没有观察到变磁性转变,在掺杂量x=0.2附近可能存在变磁性临界终点。A series of polycrystalline sample SmCo1-xFexAsO（x=0,0.05,0.1,0.2） was prepared by a solid-state reaction method.X-ray diffraction patterns indicate that all the samples have formed the ZrCuSiAs-type structure.The decrease of the lattice constant a and the increase of c are observed with the increased doping amount.Magnetic measurement results show that complicated magnetism consists of antiferromagnetic,ferromagnetic and paramagnetic between 5 and 300 K.Strong irreversibility in M-T curve is observed just below the Curie temperature.With Fe content increasing,antiferromagnetic order of SmCoAsO is suppressed,and its ferromagnetism is enhanced.M-H curves show that metamagnetic transition occurs below their antiferromagnetic transition temperature for samples with x0.2,and the transition field decreases with increasing Fe content.When Fe content reaches to 0.2,no metamagnetic transition can be observed down to 5 K.All of the results are consistent with the existence of a metamagnetic critical end point at critical concentration which is close to 0.2.

关 键 词：SmCoAsO FE掺杂 ZrCuSiAs四方结构 磁性质 

分 类 号：O614.337[理学—无机化学]