Multiple spin switching and magnetocaloric effects in orthoferrite Yb0.25Tb0.75FeO3 single crystal

Abstract

YbFeO3 exhibits spin switching (SSW) and spin reorientation transition (SRT) at low temperatures, but its mediocre magnetocaloric properties limit its further applications. As for TbFeO3 showing a large magnetocaloric effect, its SSW is missing. Motivated by this, we chemically put Yb and Tb with a ratio of 1:3 on the rare-earth site. Potential applications of magnetic and magnetocaloric properties are both preserved in one single phase Yb0.25Tb0.75FeO3, which is exceptional among the rare-earth orthoferrites. Spin switching temperature (TSSW) in the field-cooled-cooling mode increases to around 100 K compared with YbFeO3. A novel multiple SSW emerges in the field-cooled-warming mode originating from the complex competing magnetic interactions between Yb/Tb and Fe sublattices. We also addressed the mechanism of spin modification of magnetic ions with temperatures. Arrott plots created from the isothermal magnetization curves demonstrate that SRT is a second-order phase transition. The negative entropy change (refrigeration capacity) vs. temperatures [−∆Sm(RC) vs. T] diagrams indicate that the −∆Sm(RC) are effectively increased compared with YbFeO3 by rare-earth doping. The pronounced magnetic refrigeration performance and SSW effect with a low-field dependence make it promising to be employed in both magnetic sensing and refrigeration devices.