Evidence for single-gap superconductivity in Mg(B1-xCx)2 single crystals with x=0.132 from point-contact spectroscopy -: art. no. 060503

被引：63

作者：

Gonnelli, RS

Daghero, D

Calzolari, A

Ummarino, GA

Dellarocca, V

Stepanov, VA

Kazakov, SM

Zhigadlo, N

Karpinski, J

机构：

[1] Politecn Torino, Dipartimento Fis, I-10129 Turin, Italy

[2] Politecn Torino, INFM, I-10129 Turin, Italy

[3] INFM, LAMIA, I-16152 Genoa, Italy

[4] Russian Acad Sci, PN Lebedev Phys Inst, Moscow 119991, Russia

[5] ETH, Solid State Phys Lab, CH-8093 Zurich, Switzerland

来源：

PHYSICAL REVIEW B | 2005年 / 71卷 / 06期

关键词：

D O I：

10.1103/PhysRevB.71.060503

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We report the results of the first directional point-contact measurements in Mg(B1-xCx)(2) single crystals with 0.047 <= x <= 0.132. The two-gap superconductivity typical of MgB2 persists,up to x=0.105. In this region, the values of the gaps Delta(sigma) and Delta(pi) were determined by fitting the Andreev-reflection conductance curves with a two-band Blonder-Tinkham-Klapwijk (BTK) model, and confirmed by the single-band BTK fit of the sigma- and pi-band conductances, separated by means of a magnetic field. At x=0.132, when T-c = 19 K, we clearly observed the merging of the two gaps into one of amplitude Delta similar or equal to 3 meV.

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共 20 条

[1] Crystal chemistry of carbon-substituted MgB2 [J].

Avdeev, M ;

Jorgensen, JD ;

Ribeiro, RA ;

Bud'ko, SL ;

Canfield, PC .

PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 2003, 387 (3-4) :301-306

[2] Multiband model for tunneling in MgB2 junctions -: art. no. 180517 [J].

Brinkman, A ;

Golubov, AA ;

Rogalla, H ;

Dolgov, OV ;

Kortus, J ;

Kong, Y ;

Jepsen, O ;

Andersen, OK .

PHYSICAL REVIEW B, 2002, 65 (18) :1805171-1805174

[3] The substitutional chemistry of MgB2 [J].

Cava, RJ ;

Zandbergen, HW ;

Inumaru, K .

PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 2003, 385 (1-2) :8-15

[4]

Erwin SC, 2003, PHYS REV B, V68, DOI 10.1103/PhysRevB.68.132505

[5] Magnetic-field dependence of the gaps in a two-band superconductor:: A point-contact study of MgB2 single crystals -: art. no. 100504 [J].

Gonnelli, RS ;

Daghero, D ;

Calzolari, A ;

Ummarino, GA ;

Dellarocca, V ;

Stepanov, VA ;

Jun, J ;

Kazakov, SM ;

Karpinski, J .

PHYSICAL REVIEW B, 2004, 69 (10)

[6] Direct evidence for two-band superconductivity in MgB2 single crystals from directional point-contact spectroscopy in magnetic fields -: art. no. 247004 [J].

Gonnelli, RS ;

Daghero, D ;

Ummarino, GA ;

Stepanov, VA ;

Jun, J ;

Kazakov, SM ;

Karpinski, J .

PHYSICAL REVIEW LETTERS, 2002, 89 (24)

[7] Systematic study of two-band/two-gap superconductivity in carbon-substituted MgB2 by point-contact spectroscopy -: art. no. 064520 [J].

Holanová, Z ;

Szabó, P ;

Samuely, P ;

Wilke, RHT ;

Bud'ko, SL ;

Canfield, PC .

PHYSICAL REVIEW B, 2004, 70 (06) :064520-1

[8] Carbon substitution in MgB2 single crystals:: Structural and superconducting properties -: art. no. 024533 [J].

Kazakov, SM ;

Puzniak, R ;

Rogacki, K ;

Mironov, AV ;

Zhigadlo, ND ;

Jun, J ;

Soltmann, C ;

Batlogg, B ;

Karpinski, J .

PHYSICAL REVIEW B, 2005, 71 (02)

[9] Band filling and interband scattering effects in MgB2:: Carbon versus aluminum doping -: art. no. 027002 [J].

Kortus, J ;

Dolgov, OV ;

Kremer, RK ;

Golubov, AA .

PHYSICAL REVIEW LETTERS, 2005, 94 (02)

[10] Carbon-substituted MgB2 single crystals [J].

Lee, S ;

Masui, T ;

Yamamoto, A ;

Uchiyama, H ;

Tajima, S .

PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 2003, 397 (1-2) :7-13