Pr_2AlFe_(13)Mn_3化合物的反常热膨胀性质  

Thermal Expansion Anomaly of Pr2AlFe13Mn3 Compound

作　　者：段晓英[1] 

机构地区：[1]河北工业大学化工学院,天津300130

出　　处：《河北工业大学学报》2002年第4期69-72,共4页Journal of Hebei University of Technology

基　　金：河北省教委高校发展基金资助项目(2001108)

摘　　要：通过X射线衍射及磁测量实验研究了Pr2AlFe16-xMnx化合物的结构.结果表明,该系列化合物具有Th2Zn17型结构;随着锰替代量的增加,化合物的单胞体积呈现先小后大的非线性增加,这表明该类化合物在其磁相变点附近存在较大的正的本征磁致伸缩.进一步对Pr2AlFe13Mn3化合物进行的变温X射线衍射研究表明,该化合物在其居里点附近（180～198K）存在负热膨胀现象,其热膨胀系数为-3.6X10-4K-1.本文对这种性质进行了讨论.Structure properties of Pr2AlFe16-xMnx (x=0-10) compounds have been investigated by means of X-ray diffraction and magnetization measurements. The Pr2AlFe16-xMnx compounds have a rhombohedral Th2Zn17-type structure. Their unit-cell volume increase slowly with increasing x, then rapidly with the further increase of x.This implies there is a positive spontaneous volume magnetostriction in the magnetic state for Pr2AlFe16-xMnx compounds. X-ray diffraction of Pr2AlFe13Mn3 compound from 160 to 300 K shows that there appears a negative coefficient of thermal expansion, (?)≈ -3.6x10-4 K-1, from 180 to 198K and the details are discussed.

关 键 词：Pr2AlFe13Mn3化合物 X射线衍射 负热膨胀 居里温度 本征磁致伸缩 磁测量 镨铝铁锰化合物 合金学 反常热膨胀材料 

分 类 号：TG131[一般工业技术—材料科学与工程]