Superconductivity in the presence of disorder in skutterudite-related La3Co4Sn13 and La3Ru4Sn13 compounds: Electrical transport and magnetic studies

JOURNAL OF ALLOYS AND COMPOUNDS

卷:646

Article

Slebarski, A.¹  Maska, M. M.¹  Fijalkowski, M.¹  McElroy, C. A.²  Maple, M. B.² 

[1] Silesian Univ, Inst Phys, PL-40007 Katowice, Poland

[2] Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA

关键词: Superconductivity;    Atomic disorder;    Heavy fermions;    Strongly correlated electron systems;   

DOI  :  10.1016/j.jallcom.2015.06.198

来源: Elsevier

【 摘 要 】

La3Co4Sn13 and La3Ru4Sn13 were categorized as BCS superconductors. In a plot of the critical field H-c2 vs T, La3Ru4Sn13 displays a second superconducting phase at the higher critical temperature T-c(star), characteristic of inhomogeneous superconductors, while La3Co4Sn13 shows bulk superconductivity below T-c. We observe a decrease in critical temperatures with external pressure and magnetic field for both compounds. Additionally, for La3Ru4Sn13 we find that dT(c)(star)/dP > dT(c)/dP. The pressure dependences of T-c are interpreted according to the McMillan theory and understood to be a consequence of lattice stiffening. The investigation of the superconducting state of La3CoxRu4-xSn13 shows a T-c(star) that is larger then T-c for x < 4. This unique and unexpected observation is discussed as a result of the local disorder and/or the effect of chemical pressure when Ru atoms are partially replaced by smaller Co atoms. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

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