Superconductivity in the correlated pyrochlore Cd2Re2O7 -: art. no. 180503
Superconductivity in the correlated pyrochlore Cd2Re2O7 -: art. no. 180503
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DOI：
10.1103/physrevb.64.180503
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发表时间：
2001-11-01
影响因子：
3.7
通讯作者：
Mandrus, D
中科院分区：
文献类型：
--
作者：
Jin, R;He, J;Mandrus, D
本文报道了在具有室温烧绿石结构的高质量Cd_2Re_2O_7单晶中观察到的超导电性。电阻率和交流磁化率测量确定起始转变温度Tc（onset）= 1.47 K，转变宽度Δ T（c）= 0.25 K。在外加磁场中。电阻转变显示II型特征。具有近似线性的温度依赖性的上临界场H-c2。通过比热跃变（Δ C = 37.9mJ/mol·K）证实了超导体的体相性质。使用从正常状态比热数据中提取的伽马值。我们得到Δ C/γ T（c）= 1.29。接近弱耦合BCS值。在正常状态下，低于100 K的负霍尔系数表明这种材料中存在类电子传导。电阻率在2 ~ 60 K之间呈二次T关系。也就是说，rho = rho（0）+ AT（2），表示费米液体行为。Kadowaki-Woods比A/gamma（2）和Wilson比的值与强相关材料的值相当。
We report the observation of superconductivity in high-quality Cd2Re2O7 single crystals with room-temperature pyrochlore structure. Resistivity and ac susceptibility measurements establish an onset transition temperature T-c(onset) = 1.47 K with transition width DeltaT(c) = 0.25 K. In applied magnetic field. the resistive transition shows a type-II character. with an approximately linear temperature-dependence of the upper critical field H-c2. The bulk nature of the superconductivity is confirmed by the specific heat jump with DeltaC =3 7.9 mJ/mol-K. Using the gamma value extracted from normal-state specific heat data. we obtain DeltaC/gammaT(c), = 1.29. close to the weak coupling BCS value. In the normal state, a negative Hall coefficient below 100 K suggests electronlike conduction in this material. The resistivity exhibits a quadratic T dependence between 2 and 60 K. i.e., rho = rho (0) + AT(2), indicative of Fermi-liquid behavior. The values of the Kadowaki-Woods ratio A/gamma (2) and the Wilson ratio are comparable to that for strongly correlated materials.