Christian A B, Schye A T, White K O, Neumeier J J
Physics Department, Montana State University, Bozeman, MT 59717-3840, United States of America.
J Phys Condens Matter. 2018 May 16;30(19):195803. doi: 10.1088/1361-648X/aab884. Epub 2018 Mar 21.
The magnetic, thermal, and optical properties of single-crystalline CoTaO and FeTaO are reported. Optical dichroism was observed in CoTaO. Magnetic susceptibility χ(T) measurements reveal long-range antiferromagnetic order with Néel temperatures [Formula: see text] K and 8.11(5) K, respectively, and anisotropy in χ. The thermal expansion coefficients exhibit significant anisotropy and the influence of the magnetic ions and long-range order. A structural phase transition to orthorhombic occurs below T for FeTaO. Magnetic field H lowers T with its affect largest when H is directed along either [1 1 0] or [1 [Formula: see text] 0], and smallest when directed along [0 0 1]. This leads to an anisotropic magnetocaloric effect that is investigated through measurements of the specific heat and magnetization in applied magnetic field.
