Experimental determination of superconducting parameters for the intermetallic perovskite superconductor MgCNi3 -: art. no. 094502

被引:104
作者
Mao, ZQ
Rosario, MM
Nelson, KD
Wu, K
Deac, IG
Schiffer, P
Liu, Y
He, T
Regan, KA
Cava, RJ
机构
[1] Penn State Univ, Dept Phys, University Pk, PA 16802 USA
[2] Princeton Univ, Dept Chem, Princeton, NJ 08540 USA
[3] Princeton Univ, Princeton Mat Inst, Princeton, NJ 08540 USA
[4] Peking Univ, Dept Phys, Beijing 100871, Peoples R China
[5] Univ Babes Bolyai, Dept Phys, R-3400 Cluj Napoca, Romania
关键词
D O I
10.1103/PhysRevB.67.094502
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
We have measured upper-critical-field H-c2, specific heat C, and tunneling spectra of the intermetallic perovskite superconductor MgCNi3 with a superconducting transition temperature T(c)approximate to7.6 K. Based on these measurements and relevant theoretical relations, we have evaluated various superconducting parameters for this material, including the thermodynamic critical field H-c(0), coherence length xi(0), penetration depth lambda(0), lower-critical-field H-c1(0), and Ginzburg-Landau parameter kappa(0). From the specific heat, we obtain the Debye temperature Theta(D)approximate to284 K. We find a jump of DeltaC/gammaT(c)=2.1 at T-c (where gamma is the normal-state electronic specific coefficient), which is larger than the weak-coupling BCS value of 1.43, suggesting that MgCNi3 may be a strong-coupling superconductor. In addition, we observed a pronounced zero-bias conductance peak (ZBCP) in the tunneling spectra. We discuss the possible physical origins of the observed ZBCP.
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页数:6
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