Magnetoelastic studies of Nd₀,₇₅Dy₀,₂₅Fe₃(BO₃)₄ in the external magnetic field: Magnetic phase transitions

Abstract

We report on results of sound-velocity and sound-attenuation measurements in the Nd₀,₇₅Dy₀,₂₅Fe₃(BO₃)₄ in external magnetic fields up to 5 T, applied along several directions with respect to crystallographic axes, and at temperatures down to 1.7 K. The experimental data are analyzed with a microscopic theory based on exchange-striction coupling and phenomenological theory resulting in a qualitative agreement between theoretical results and experimental data.