Y_（1－x）Pr_xBa_2Cu_3O_7系统的低温电子比热的研究  

STUDY OF LOW TEMPERATURE ELECTRONIC SPECIFIC HEAT OF Y_(1-x)Pr_xBa_2Cu_3O_7

作　　者：宋永伟 周晖[1] 王玉鹏[1] 雒建林[1] 陈彤蔡晓航 范小波[1] 冉启泽[1] 金锋 赵忠贤[1] 

机构地区：[1]中国科学院低温技术实验中心,中国科学院物理研究所

出　　处：《低温物理学报》1995年第1期57-62,共6页Low Temperature Physical Letters

基　　金：国家超导中心和中科院超导办资助

摘　　要：我们对Ｙ１－ｘＰｒｘＢａ２Ｃｕ３Ｏ７（ｘ＝０．２，０．４５，０．６）样品的比热进行了研究，发现在这个系统中比热线性项系数非常大，呈现出重费米子的特征，并且不同温区其数值亦不同．比热的结果表明Ｐｒ离子在这个系统中基本上处于＋３价．对实验数据进行了仔细分析，我们认为比热线性项增大是源于Ｐｒ离子掺入后这个系统中出现了Ｋｏｎｄｏ效应以及由此而产生的空穴局域态，也正是局域态的出现，导致了金属绝缘体转变，同时导致了超导电性的破坏．Abstract Low temperature speific heat measurement as a function of temperature are reported for y1-xPrxBa2Cu3O7 compounds with x= 0. 2, 0. 45, 0. 6. In these compounds, Coefficient of linear term is very large, suggestive of heavy-fermion-like behsvior, and it has different values at different temperature ranse. The results of specific heat measurement show that the valence of the praseodymium ions is close to + 3 in this system. Carefully analysing the experiment data,we mink the large linear term coefficient may be attributed to Kondo interaction between Pr3+magnetic momet and mobile hole. This leads to the loclhation and eventually to the metal- insulator trasition and Tc suppression with Pr-doping in this system.

关 键 词：超导电性 YBCO PR 比热 

分 类 号：TM262[一般工业技术—材料科学与工程] O513[电气工程—电工理论与新技术]