Manganese substitution effects in SmFeO3 nanoparticles fabricated by self-ignited sol–gel process

Abstract

Through the optimization of process, a series of orthorhombic perovskite SmFe1−x Mn x O3 (x = 0, 0.05, 0.1, 0.15, 0.2, 0.25) nanoparticles were readily prepared by self-ignited sol–gel process. The Mn substitution effects on the structure, morphology and magnetic properties of SmFeO3 have been investigated in detail. Pure phase orthorhombic SmFeO3 is calcinated at 900 °C for 3 h. By the introduction of Mn3+, the synthesis temperature of orthorhombic perovskite-type SmFe1−x Mn x O3 particles has been lowered to be around 700 °C. At room temperature, weak ferromagnetic behavior is observed at SmFeO3 which is caused by its canted antiferromagnetic ordering. In the SmFe1−x Mn x O3 system for x ≤ 0.15, the weak ferromagnetic interactions are effectively enhanced with increasing Mn3+, showing increased magnetization and coercive field. However, for SmFe0.8Mn0.2O3 and SmFe0.75Mn0.25O3, the weak ferromagnetic couplings begin to decrease. SmFe0.85Mn0.15O3 displays the strongest ferromagnetic behavior. This peculiar behavior is ascribed to the complex magnetic interactions between Mn and Fe ions. A series of orthorhombic perovskite SmFe1−x Mn x O3 (0 ≤ x ≤ 0.25) nanopowders were readily prepared by self-ignited sol–gel process. The calcination temperature has been lowered to be around 700 °C by the introduction of Mn3+. SmFe0.85Mn0.15O3 displays the strongest ferromagnetic behavior. The tunability of the magnetic characteristics of SmFe1−x Mn x O3 is ascribed to the complex magnetic interactions between Mn and Fe ions.