Magnetic-crystallographic p,T-phase diagram of Fe_1.141Te: A high-pressure neutron diffraction study

The crystal and magnetic structures of Fe_1.141Te have been studied by neutron powder diffraction in the temperature range from 5 to 106 K and pressures in the range from ambient to ∼2.7 GPa. The p,T-phase diagram contains three phases with monoclinic, orthorhombic, and tetragonal symmetry. The monoclinic phase was found to be stable for T 2.16 GPa. The monoclinic phase shows commensurate bicollinear antiferromagnetic order with propagation vector k = (1/2 0 1/2), while the orthorhombic phase is incommensurately antiferromagnetically ordered with propagation vector k = (1/2-δ 0 1/2). The δ-parameter increases linearly with the pressure for 0.4 or similar 2.1 GPa and temperatures less than ∝68 K, depending on the pressure. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)