摘要
以商业纯Gd为原料,采用非自耗电弧炉氩气保护下熔炼了Gd5Si2Ge2-xSn(xx=0.2,0.5,1)和Gd5Si2-yGe2Sny(y=0.1,0.2,0.5)系列合金,研究Sn合金化对Gd5Si2Ge2晶体结构和磁热性能的影响。粉末XRD结果表明:Sn代Ge样品具有正交Gd5Si4型结构;Sn少量代Si(y=0.1,0.2)的样品具有单斜Gd5Si2Ge2型结构;Gd5Si1.5Ge2Sn0.5则为单斜和正交的混合结构。用超导量子磁强计(SQUID)测定了样品的M-T和不同温度的M-H曲线,结果表明:Gd5Si2Ge2-xSnx(x=0.2,0.5,1)不具有巨磁热效应;Gd5Si1.9Ge2Sn0.1合金的最大磁熵变达15.3J/kg·K(0T^5T),具有巨磁热效应。
Alloys of Gd5Si2Ge2-xSnx （x=0.2, 0.5, 1） and Gd5Si2-yGe2Sny （y=0.1, 0.2, 0.5） were prepared by arc melting under argon atmosphere with the use of commercial gadolinium. The results of powder X-ray diffraction show that, Gd5Si2Ge2-xSnx （x=0.2, 0.5, 1） have the orthorhombic GdsSi4-type structure, and Gd5Si2Ge2-xSnx series alloys have the low magnetic entropy changes due to the appearance of Gd5Si4-type structure. With the replacement of silicon by a little Tin（y=0.1, 0.2）,the alloys have the monoclinic Gd5Si2Ge2 type structure, and Gd5Si15Ge2Sn0.5 has the mix structure of monoclinic Gd5Si2Ge2-type and orthorhombic Gd5Si4-type structure. SQUID was used to measure the magnetocaloric effect of the samples. Gd5Si2-yGe2Sny （y=0.1） has a giant magnetocaloric effect with the maximum magnetic entropy change of 15.3 J/kg·K （0 T-5 T）.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2005年第10期1528-1531,共4页
Rare Metal Materials and Engineering
基金
国家"863"项目(2002AA324010)资助
关键词
Gd5Si2Ge2
磁热效应
磁致冷材料
晶体结构
磁熵变
Gd5Si2Ge2
magnetocaloric effect
magnetic refrigation material
crystal structure
magnetic entropy change
