Multiple gaps revealed by low temperature specific heat in the 1111-type CaFe0.88Co0.12AsF single crystals

Jianan Chu; Teng Wang; Yonghui Ma; Jiaxin Feng; Lingling Wang; Xuguang Xu; Wei Li; Gang Mu; Xiaoming Xie

doi:10.1088/1361-648X/ab34b8

Multiple gaps revealed by low temperature specific heat in the 1111-type CaFe_0.88Co_0.12AsF single crystals

J Phys Condens Matter. 2019 Nov 13;31(45):455602. doi: 10.1088/1361-648X/ab34b8. Epub 2019 Jul 25.

Authors

Jianan Chu¹, Teng Wang, Yonghui Ma, Jiaxin Feng, Lingling Wang, Xuguang Xu, Wei Li, Gang Mu, Xiaoming Xie

Affiliation

¹ State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, People's Republic of China. CAS Center for Excellence in Superconducting Electronics (CENSE), Shanghai 200050, People's Republic of China. University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.

PMID: 31341099
DOI: 10.1088/1361-648X/ab34b8

Abstract

Low-temperature specific heat (SH) is measured on the 1111-type CaFe_0.88 Co_0.12AsF single crystals under different magnetic fields. A clear SH jump with the height [Formula: see text] mJ mol^-1 K^-2 is observed at the superconducting transition temperature T _c . The electronic SH coefficient [Formula: see text] increases linearly with the field below 5 T and a kink is observed around 5 T, indicating a multi-gap feature in the present system. Such a sign is also reflected in the T _c - B data. A detailed analysis shows that this behavior can be interpreted in terms of a two-gap scenario with the ratio [Formula: see text]-4.5.