Cr_(1-x)P_(x)合金的结构与磁性

Structural and Magnetic Properties of Cr_(1-x)P_(x) Alloys

采用固相烧结法制备了Cr_(1-x)P_(x)(x=0.01~0.1)系列合金,系统研究了其成分、晶体结构、磁性和磁相变的相互影响关系。同时用熔炼法制备Cr_(1-x)Si_(x)合金进行对比。粉末X射线衍射和SEM/EDX实验结果表明,当x<0.03时,Cr_(1-x)P_(x)系列合金为单相性较好的立方结构(空间群为Im-3m)。Cr_(1-x)P_(x)系列合金的固溶度约为3%,大于3%时Cr-P以析出相(Cr_(3)P)的形式存在。磁性和DSC测量表征奈尔温度、热滞和磁相变的结果表明,掺杂少量P元素使Cr_(1-x)P_(x)系列合金的奈尔温度降低。Cr_(0.98)P_(0.02)和Cr_(0.985)Si_(0.015)合金具有反铁磁-顺磁的磁相变,伴随着热滞,具有一级相变的特征。

A series of Cr_(1-x)P_(x)(x=0.01~0.1)alloys were prepared with solid phase sintering and arc-melting as control for comparison to investigate the mutual influence of their composition,crystal structure,magnetic properties and magnetic phase transition.The results of powder X-ray diffraction and SEM/EDX analysis showed that the Cr_(1-x)P_(x)alloys were single phase cubic structure with space group Im-3m when x<0.03;The solubility limit in Cr_(1-x)P_(x)alloys was about 3%,and the Cr-P compound appeared as phase(Cr_(3)P)when P content was larger than 3%.Néel temperature,thermal hysteresis and magnetic phase transition of above alloys were characterized using magnetic and DSC measurements.It is shown that Néel temperature of Cr_(1-x)P_(x)alloys decreases when doping small amount of P element.The Cr_(0.98)P_(0.02 )and Cr_(0.985)Si_(0.015) alloys show an antiferromagnetic-paramagnetic magnetic phase transition,accompanied by a finite thermal hysteresis,which is characteristic of a first-order phase transition.