The giant magnetocaloric effect in Gd_(5)Si_(2)Ge_(2)with low purity gadolinium

查看全文 作　　者：ZHANG [1]Tiebang;CHEN [1]Yungui;FU [1]Hao;TENG [2]Baohua;TANG [1]Yongbai;TU [1]Mingjing 机构地区：[1]School of Materials Science and Engineering, Sichuan University, Chengdu 610065, China;[2]Department of Physics, National University of Singapore, Singapore117542, Republic of Singapore 出　　处：《Chinese Science Bulletin》索引2005年第50卷第16期,共4页 基　　金：This work was supported by the National High Technology Research and Development Program of China(No.2002AA324010). 摘　　要：The giant magnetocaloric effect Gd5Si2Ge2 alloy was prepared with 99wt% low purity commercial Gd. Pow-der XRD and magnetic measurements showed that the Gd5Si2Ge2 alloy annealed at 1200℃ for 1 h had a significant magnetic- crystallographic first order phase transition at about 270 K. The maximal magnetic entropy change is 17.55 J·kg?1·K?1 under a magnetic field change of 0―5 T. The distinct increase of magnetic entropy change belongs to the first-order phase transition from the orthorhombic Gd5Si4-type to the monoclinic Gd5Si2Ge2-type after high temperature heat-treatment. 关 键 词：Gd5Si2Ge2 磁热 钆合金 熵变换