Open AccessEvolution of the superconducting properties inFeSe 1 − x S x
Author(s) -
Steven A. Moore,
J. Curtis,
C. Di Giorgio,
Eric Lechner,
M. Abdel-Hafiez,
О. С. Волкова,
A. N. Vasiliev,
Д. А. Чареев,
G. Karapetrov,
M. Iavarone
Publication year - 2015
Publication title -
physical review. b, condensed matter and materials physics
Language(s) - English
Resource type - Journals
eISSN - 1538-4489
pISSN - 1098-0121
DOI - 10.1103/physrevb.92.235113
Subject(s) - anisotropy , ionic radius , superconductivity , condensed matter physics , materials science , valence (chemistry) , physics , ion , optics , quantum mechanics
We present scanning tunneling microscopy and spectroscopy measurements on FeSe1-xSx single crystals with x=0, 0.04, and 0.09. The S substitution into the Se site is equivalent to a positive chemical pressure, since S and Se have the same valence and S has a smaller ionic radius than Se. The subsequent changes in the electronic structure of FeSe induce a decrease of the structural transition temperature and a small increase in the superconducting critical temperature. The evolution of the gaps with increasing S concentration suggests an increase of the hole Fermi surface. Moreover, the vortex core anisotropy, that likely reflects the Fermi surface anisotropy, is strongly suppressed by the S substitution