Temperature-induced spin reorientation and magnetization jump of rare-earth orthoferrite Ho_0.5Pr_0.5FeO₃ single crystal

We report temperature-induced spin reorientation and magnetization jump effects in the rare earth (RE) orthoferrite Ho_0.5Pr_0.5FeO₃ single crystal. The single crystal of about 6 mm in diameter and 50 mm in length was successfully grown by optical floating zone method. Both X-ray diffraction and Laue photograph confirmed the homogeneity and high quality of the crystal. Magnetic properties of Ho_0.5Pr_0.5FeO₃ single crystal are studied over a wide temperature range from 2 to 300 K. Spin reorientation transition from Γ₂ to Γ₄ phase is observed in the temperature range of 75-90 K. At lower temperature, the Ho_0.5Pr_0.5FeO₃ shows an abrupt jump of magnetization along the a-axis, which occurs only in the field-cooling process, and is sensitive to external applied magnetic field. By analyzing the jump temperature and magnitude of the magnetization, we conclude that it is caused by the spin reversal of the rare earth ions. The isothermal magnetization versus field hysteresis loop measurements along a axis explain the spin configuration variation from 3 K to 60 K.