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, SmFeO₃shows a magnetization rotation from thecaxis above 480 K to theaaxis below 450 K, known as the Γ₄→ Γ₂transition. This work reports the successful synthesis of the new single-crystal perovskite SmFe_0.75Mn_0.25O₃and finds interesting spin reorientations above and below room temperature. In addition to the spin reorientation of the Γ₄→ Γ₂magnetic phase transition observed at aroundT_SR2= 382 K, a new spin reorientation, Γ₂→ Γ₁, was seen at aroundT_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–TandM–Hmeasurements have been made to study the temperature and magnetic-field dependence of the observed spin reorientation transitions.