Magnetic Interaction between Pr3+ and Dy3+ Spins and Their Spin Transition Induced by Magnetic Field in a Dy0.5Pr0.5FeO3 Single Crystal
2019 American Chemical Society. Rare-earth orthoferrites are receiving ever-increasing attention for their potential applications in magneto-optical switching, multiferroics, and novel physics originating from complicated interactions between magnetic rare-earth and iron ions. In this work, a Dy0.5Pr0.5FeO3 single crystal was studied in comparison with DyFeO3 and PrFeO3 single crystals to ascertain the effects of interactions between rare-earth spins in Dy0.5Pr0.5FeO3 on its magnetic properties. Dy3+ and Pr3+ spins do not behave as separate entities in Dy0.5Pr0.5FeO3. The interaction between them was found to be the strongest below their antiferromagnetic ordering temperature. However, this interaction still persists to substantially higher temperatures. While the ordering temperature of Dy3+ spins is field-independent for DyFeO3, it becomes strongly field-dependent for Dy0.5Pr0.5FeO3. External field produces field polarization of nonordered rare-earth spins below ∼25 K for all three systems. High-field-induced spin transition of rare-earth spins was observed for Dy0.5Pr0.5FeO3 when a large field H ≥ 3.5 T is oriented along the crystalline a-axis at temperatures below and above the ordering temperature of the rare-earth spins, while the Fe3+ spin structure was not affected. This is different from the field-induced spin reorientation of the Dy3+ spin structure in DyFeO3, which occurs only when Dy3+ spins are ordered. The complicated behavior of rare earths uncovered in this work further deepens the understanding of such a complex material system.