Modulation of magnetic transitions in SmFeO3 single crystal by Pr3+ substitution

In this paper, multiple magnetic transitions of Sm0.5Pr0.5FeO3 single crystal were systematically studied. By substituting Pr3+ in SmFeO3, spin reorientation temperature (TSR) was effectively decreased from 450 K-480 K (SmFeO3) to 180 K-220 K (Sm0.5Pr0.5FeO3). When the applied magnetic field is 500 Oe, spin switching was observed at 119 K (Tssw) for Sm0.5Pr0.5FeO3 and 180 K for SmFeO3, in which a spontaneous spin-flip transition of Sm/Pr- and Fe-sublattices at the same time, accompanied by an exchange of their FM vector directions. The compensation temperature (Tcomp) was raised from 4 K to 90 K which corresponds to zero magnetization. The possible mechanism for the modulation of magnetic transitions in SmFeO3 single crystal by Pr3+ substitution is discussed in detail. The dynamics of spin reorientation for Sm0.5Pr0.5FeO3 is also verified by Terahertz time-domain spectroscopy (THz-TDS), with the resonant excitation of quasi-antiferromagnetic (AFM) mode.