Magnetic properties of nanocrystalline Ni-Zn ferrites doped with samarium

We describe the influence of the temperature of sintering on the structure and the static magnetic properties in Ni0.5Zn0.5Sm x Fe2-x O4 ferrites prepared by combustion synthesis. The increase in Sm content increases the lattice parameter and decreases the mean grain size. The material treated at 600 deg. C should be single spinel ferrite but with low magnetization saturation. Calcinations carried out at 800 and 1000 deg. C resulted in materials with cubic spinel phase, but a small amount of SmFeO3 was also formed. A smooth diminution of the saturation magnetization with an increase in Sm amount was observed. The highest Curie temperatures were obtained for sample treatment at 1000 deg. C with higher Sm content