Open AccessMagnetic neutron scattering studies on the Fe-based superconductor system Fe1+yTe1-xSex
Author(s) -
李世超,
甘远,
王靖珲,
冉柯静,
温锦生
Publication year - 2015
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.64.097503
Subject(s) - antiferromagnetism , superconductivity , condensed matter physics , magnetism , tetragonal crystal system , neutron scattering , neutron diffraction , physics , spin (aerodynamics) , materials science , scattering , phase (matter) , diffraction , quantum mechanics , thermodynamics
We preflent a brief overview on the interplay between magnetism and superconductivity in one of the Fe-based superconductor systems, Fe1+yTe1-xSex. The parent compound Fe1+y Te is an antiferromagnet; with Se doping, antiferromagnetic order is suppressed, followed by the appearance of superconductivity; optimal superconductivity is achieved when x50%, with a superconducting temperature Tc of 15 K. The parent compound has an in-plane magnetic ordering wave vector around (0.5, 0) (using the tetragonal notation with two Fe atoms per cell). As Se concentration increases, the spectral weight appears to shift to the wave vector around (0.5, 0.5), accompanying the optimization of superconductivity. A neutron-spin resonance is observed around (0.5, 0.5) below Tc, and is suppressed, along with superconductivity, by an external magnetic field. Taking these evidences into account, we conclude that magnetism and superconductivity in this system couple to each other closely-while the static magnetic order around (0.5, 0) competes with superconductivity, the spin excitations around (0.5, 0.5) may be an important ingredient for it. We also discuss the nature of magnetism and substitution effects of 3d transition metals.