Spin-reorientation magnetic transitions in Mn-doped SmFeO 3

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, SmFeO 3 shows a magnetization rotation from the c axis above 480K to the a axis below 450K, known as the ? 4 -> ? 2 transition. This work reports the successful synthesis of the new single-crystal perovskite SmFe 0.75 Mn 0.25 O 3 and finds interesting spin reorientations above and below room temperature. In addition to the spin reorientation of the ? 4 -> ? 2 magnetic phase transition observed at around T SR2 = 382K, a new spin reorientation, ? 2 -> ? 1, was seen at around T SR1 = 212K 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.