Structural features and temperature-dependent magnetic response of cobalt ferrite nanoparticle substituted with rare earth sm3+

A series of samarium doped cobalt ferrites with the nominal compositions of CoSmxFe2-xO4 (where x = 0, 0.02, 0.04, and 0.06 at.%) was synthesized using sol-gel auto-combustion method. The crystal structure, morphology and magnetic properties of the nanoparticles have been investigated. The XRD data analyzed by the MAUD program confirmed the successful substitution of Fe3+ by Sm3+ cations in the unit cell of the cobalt ferrite lattice. The formation of nanosized spinel ferrites was confirmed by FESEM and FTIR analysis. The values of saturation magnetization (M-S) decreased from 76 emu/g to 63 emu/g by increasing the Sm content from x = 0 to x = 0.06 at room temperature, whereas at 10 K, the decreasing tendency of MS was much weaker. The reduction of temperature from 300 to 10 K caused a remarkable growth of both the saturation magnetization and coercive field (H-C). The coercivity of the sample with x = 0.06 at 10 K is strongly higher than the one at the room temperature. The influence of samarium ions and temperature-dependent magnetic response of CoFe2O4 nanoparticles was studied and their effect was discussed in terms of the geometrical proportions and magnetic anisotropy evolutions. The Sm doped cobalt ferrite is a suitable candidate for moderate permanent magnets and high density information storage, especially when in use at low temperatures.

Automated summary

A series of samarium-doped cobalt ferrite nanoparticles were successfully synthesized using sol-gel auto-combustion method. The saturation magnetization decreased with increasing samarium content, but showed an improvement at lower temperatures. Samarium-doped cobalt ferrite is a suitable candidate for moderate permanent magnets and high density information storage, especially at low temperatures.