Pressure-induced phase transitions and high-pressure tetragonal phase of Fe1.08Te

TL;DR

This study investigates how hydrostatic pressure influences phase transitions in Fe1.08Te, revealing multiple structural and magnetic phase changes, including a high-pressure tetragonal phase, highlighting strong magneto-elastic coupling effects.

Contribution

It provides new insights into pressure-induced phase transitions in Fe1.08Te, including the identification of a high-pressure tetragonal phase and detailed phase behavior under varying pressures.

Findings

Multiple phase transitions observed under pressure.

Identification of a high-pressure tetragonal phase.

Strong magneto-elastic coupling effects inferred.

Abstract

We report the effects of hydrostatic pressure on the temperature-induced phase transitions in Fe1.08Te in the pressure range 0-3 GPa using synchrotron powder x-ray diffraction (XRD). The results reveal a plethora of phase transitions. At ambient pressure, Fe1.08Te undergoes simultaneous first-order structural symmetry-breaking and magnetic phase transitions, namely from the paramagnetic tetragonal (P4/nmm) to the antiferromagnetic monoclinic (P2_1/m) phase. We show that, at a pressure of 1.33 GPa, the low temperature structure adopts an orthorhombic symmetry. More importantly, for pressures of 2.29 GPa and higher, a symmetry-conserving tetragonal-tetragonal phase transition has been identified from a change in the c/a ratio of the lattice parameters. The succession of different pressure and temperature-induced structural and magnetic phases indicates the presence of strong magneto-elastic coupling effects in this material.