Magnetization, specific heat, and thermal conductivity of hexagonal ErMnO_3 single crystals

摘要

We report a study of magnetism and magnetic transitions of hexagonal ErMnO_3 single crystals by magnetization, specific heat, and heat transport measurements.Magnetization data show that the c-axis magnetic field induces three magnetic transitions at 0.8, 12, and 28 T. The specific heat shows a peak at 2.2 K, which is due to a magnetic transition of Er~(3+) moments. For low-T thermal conductivity (κ), a clear diplike feature appears in the κ(H) isotherm at 1–1.25 T for H ‖ ab, while in the case of H ‖ c, a steplike increase is observed at 0.5–0.8 T. The transition fields in κ(H) are in good agreement with those obtained from magnetization, and the anomaly of κ can be understood by a spin-phonon scattering scenario. The natures of magnetic structures and corresponding field-induced transitions at low temperatures are discussed.