Re掺杂对Hg系超导体U-J关系的影响  

THE INFLUENCE OF THE U J RELATIONSHIP OF Hg BASED SUPERCONDUCTORS BY Re DOPING

作　　者：张军[1,2] 孙学峰[1,2] 赵霞[1,2] 李晓光 

机构地区：[1]中国科学技术大学材料科学与工程系 [2]中国科学院内耗与固体缺陷开放研究实验室

出　　处：《低温物理学报》1999年第4期283-286,共4页Low Temperature Physical Letters

基　　金：国家超导中心资助项目;国家自然科学基金

摘　　要：本文研究了Ｈｇ０．７Ｃｒ０．３Ｓｒ２Ｃａ２Ｃｕ３Ｏｙ，ＨｇＢａ２Ｃａ２Ｃｕ２．９Ｒｅ０．１Ｏｙ，ＨｇＳｒ２Ｃａ３Ｃｕ３．８Ｒｅ０．２Ｏｙ的磁性，发现Ｒｅ的掺入会改变ＵＪ关系．由驰豫测量结果分析得到Ｈｇ（Ｒｅ）１２２３，Ｈｇ（Ｒｅ）１２３４具有对数钉扎势Ｕ＝Ｕ０Ｈ－ｎｌｎ（Ｊｃ０／Ｊ），其中对Ｈｇ（Ｒｅ）１２２３在２０Ｋ～６０Ｋ范围里Ｕ０和Ｊｃ０近似与温度无关；对Ｈｇ（Ｒｅ）１２３４，Ｕ０和Ｊｃ０与磁场和温度有关．而Ｈｇ１２２３具有幂次方钉扎势Ｕ＝Ｕ０（Ｊｃ０／Ｊ）μ．另外，由磁化曲线Ｍ（Ｈ）的测量得到临界电流密度随磁场的变化关系．结果表明Ｈｇ（Ｒｅ）１２２３在２０Ｋ～９０Ｋ、Ｈｇ（Ｒｅ）１２３４在２０Ｋ～７０Ｋ的温度范围内，临界电流密度随磁场的变化关系均可以用由对数钉扎势得出的Ｊｃ（Ｈ）关系很好地描述．我们认为Ｒｅ掺入引起的体系的各向异性的减小和岛状钉扎中心。Abstract Magnetic properties in Hg 0.7 Cr 0.3 Sr 2Ca 2Cu 3O y , HgBa 2Ca 2Cu 2.9 Re 0.1 O y , HgSr 2Ca 3Cu 3.8 Re 0.2 O y were investigated. It was found that the doping of Re could change U J relationship. The derived effective pinning barriers were fitted, from the experimental data, to the relation, U=U 0H -n ln (J c0 /J) , where U 0, J c0 are independent on temperature at 20K～60K for Hg(Re) 1223 and U 0, J c0 are dependent on temperature and magnetic field for Hg(Re) 1234. On the other hand, a power law U=U 0(J c0 /J) μ was obtained for Hg 1223. The dependence of critical current on magnetic field for Hg(Re) 1223 at 20K～90K and for Hg(Re) 1234 at 20K～70K can be fitted to J c(H ) formula in the logarithmic barrier framework. We suggested that the doping of Re reduces the crystal anisotropy, introduces pinning centers, thereby changes U J relationship.

关 键 词：汞系超导体 镭掺杂 U-J关系 

分 类 号：TM262.014[一般工业技术—材料科学与工程]