1209.1255 (C. Koz et al.)

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

C. Koz, S. Rößler, A. A. Tsirlin, D. Kasinathan, C. Börrnert, M. Hanfland, H. Rosner, S. Wirth, U. Schwarz

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.

View original: http://arxiv.org/abs/1209.1255