Open AccessMulti-band Superconductivity in a misfit layered compound (SnSe)1.16(NbSe2)2
Author(s) -
Hua Bai,
Lei Qiao,
Miaocong Li,
Jiang Ma,
Xiaohui Yang,
Yupeng Li,
Tao Qian,
Zhu-An Xu
Publication year - 2020
Publication title -
materials research express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 35
ISSN - 2053-1591
DOI - 10.1088/2053-1591/ab60a8
Subject(s) - paramagnetism , materials science , crystallography , physics , condensed matter physics , chemistry
We report the discovery of superconductivity with T c of about 5.3 K in a new misfit layered compound (SnSe) 1.16 (NbSe 2 ) 2 . High resolution transmission electron microscopy and selected area electron diffraction of the single-crystalline samples clearly reveal the misfit layered structure. Based on the McMillan equation, the electron-phonon coupling constant λ e – ph is estimated to be about 0.96, which is close to strong coupling range. The estimated out-of-plane and in-plane upper critical magnetic fields are 8.9 T and 15.5 T respectively. H c 2 ab (0) is 1.74 times the value of Pauli paramagnetic limit. Moreover, there is a positive curvature in the H c 2 ( T ) curves near T c , indicating a feature of multi-band superconductivity. The temperature dependence of specific-heat in superconducting state can be fit by a two-band BCS model, which confirms further the multi-band superconductivity. The reduced charge transfer between the two subsystems may account for the enhanced T c comparing with (SnSe) 1.16 (NbSe 2 ).