Magnetic phase diagram of Fe1.1Te1-xSex: A comparative study with the stoichiometric superconducting FeTe1-xSex system

TL;DR

This study compares the magnetic, superconducting, and electronic properties of Fe1.1Te1-xSex with stoichiometric FeTe1-xSex, revealing differences in magnetic phases and electronic structure through spectroscopy and phase diagram analysis.

Contribution

It provides the magnetic phase diagram of Fe1.1Te1-xSex and highlights the emergence of a spin-glass state due to Se substitution, contrasting with the stoichiometric system.

Findings

Fe1.1Te1-xSex is magnetic with a spin-glass state.

Moessbauer spectroscopy reveals electronic differences.

Magnetic phase diagram shows destabilization of antiferromagnetism.

Abstract

We report a comparative study of the series Fe1.1Te1-xSex and the stoichiometric FeTe1-xSex to bring out the difference in their magnetic, superconducting and electronic properties. The Fe1.1Te1-xSex series is found to be magnetic and its microscopic properties are elucidated through Moessbauer spectroscopy. The magnetic phase diagram of Fe1.1Te1-xSex is traced out and it shows the emergence of spin-glass state when the antiferromagnetic state is destabilized by the Se substitution. The isomer shift and quadrupolar splitting obtained from the Moessbauer spectroscopy clearly brings out the electronic differences in these two series.