Magneto-elastic effects in single-crystal USb0.8Te0.2

摘要

A high resolution X-ray diffraction study has been performed on a single crystal of USb0.8Te0.2. At room temperature this material has the cubic FCC (NaCl) structure. On cooling through the Neel point of similar to 205 K USb0.8Te0.2 is known to enter a triple-q antiferromagnetic phase. Below T-C similar to 175 K USb0.8Te0.2 is a ferromagnet with net magnetisation along the [111] body diagonal. Four-circle X-ray scattering data from high-symmetry {h0h} and {hhh} reflections are presented as a function of temperature. We confirm that this magnetisation directly leads to a magneto-elastic distortion of the crystal lattice with a rhombohedral extension along the [111] body diagonals. At 130 K, this distortion is found to correspond to a rhombohedral bond angle of alpha = 89.856 degrees +/- 0.004 degrees consistent with previous results. In this single-crystal study we also present evidence for additional associated effects which we attribute to inter-grain stresses and sample mosaic structure.