Spin-reorientation magnetic transitions in Mn-doped SmFeO3

Spin reorientation is a magnetic phase transition in which rotation of the magnetization vector with respect to the crystallographic axes occurs upon a change in the temperature or magnetic field. For example, SmFeO3 shows a magnetization rotation from the c axis above 480 K to the a axis below 450 K, known as the Gamma(4) -> Gamma(2) transition. This work reports the successful synthesis of the new single-crystal perovskite SmFe0.75Mn0.25O3 and finds interesting spin reorientations above and below room temperature. In addition to the spin reorientation of the Gamma(4) -> Gamma(2) magnetic phase transition observed at around T-SR2 = 382 K, a new spin reorientation, Gamma(2) -> Gamma(1), was seen at around T-SR1 = 212 K due to Mn doping, which could not be observed in the parent rare earth perovskite compound. This unexpected spin configuration has complete antiferromagnetic order without any canting-induced weak ferromagnetic moment, resulting in zero magnetization in the low-temperature regime. M-T and M-H measurements have been made to study the temperature and magnetic-field dependence of the observed spin reorientation transitions.