Evolution of two-step structural phase transition in Fe1+dTe detected by low-temperature x-ray diffraction

TL;DR

This study used low-temperature x-ray diffraction to reveal a two-step structural phase transition in Fe1.13Te, linking it to magnetic transitions and suggesting potential superconductivity at domain boundaries.

Contribution

It provides a detailed analysis of the two-step structural transition in Fe1.13Te and its relation to magnetic behavior, including coexistence of phases and implications for superconductivity.

Findings

Two-step structural phase transition observed: tetragonal-orthorhombic-monoclinic.

Coexistence of orthorhombic and monoclinic phases at 5 K.

Potential for superconductivity at domain boundaries.

Abstract

The low-temperature crystal structure of Fe1.13Te, which exhibits an anomalous two-step magnetic transition, was clarified by the systematic x-ray diffraction measurements. It was found that two-step structural phase transition, tetragonal-orthorhombic-monoclinic, occurred correspondingly to the two-step magnetic transition. The detailed analysis of the profile at 5 K indicated the coexistence of the minor orthorhombic area inside the major monoclinic lattice, which could explain the lower-shift (suppression) of the antiferromagnetic transition temperature in Fe1.13Te and suggest a possibility of superconductivity at the domain boundary.