Magnetic properties of Ce-Mn substituted M-type Sr-hexaferrites

Ce-Mn substituted M-type Sr-hexaferrites (SrM) of Sr1-xCexFe11-xMnxO19 and Sr1-xCexFe11-2xMn2xO19 (0 <= x <= 0.2) were synthesized by solid-state reaction routes. Ce-Mn doped SrM exhibited an increased coercivity (H-C) of similar to 5 kOe, which is 37% higher than that of non-substituted SrM (x=0). This high H-C could be obtained without reducing the saturation magnetization (M-S) when the optimally doped (x=0.1) powder samples were calcined at 1200 degrees C. The Ce Mn doped SrM samples also showed enhanced thermal stability of H-C, characterized by similar to 60% lower temperature coefficient for H-C compared to the undoped SrM. The increased H-C and the higher thermal stability of H-C are attributable to both the grain refinement and the enhancement of magneto-crystalline anisotropy in the Ce-Mn SrM. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.