Article ID Journal Published Year Pages File Type
1614145 Journal of Alloys and Compounds 2013 4 Pages PDF
Abstract

•CoFe2O4/CoFe2 composites were synthesized by reducing CoFe2O4 at 300 °C and 400 °C.•Heating temperature makes a great impact on composition and magnetic properties.•Inter-particle dipole interaction is dominant in the product of heating at 300 °C.•Inter-particle exchange interaction appears in the product of heating at 400 °C.

CoFe2O4/CoFe2 composite nano-particles were synthesized by heating CoFe2O4 nano-particles in reducing atmosphere at 300 °C and 400 °C. Their composition, microstructure and magnetic properties were investigated. It was found that the product of reducing CoFe2O4 at 300 °C is composed by CoFe2O4 nano-particles and a small amount of CoFe2 nano-alloy. Based on the negative values of Henkel plots and the two-phase behavior in magnetic hysteresis loop the dominant inter-particle dipole coupling was confirmed. But in the process of reducing CoFe2O4 at 400 °C, surface layers of CoFe2 were formed on the CoFe2O4 nano-particles, and exchange coupling appeared at the interface of both phases, which was confirmed from the positive values of Henkel plots.

Related Topics
Physical Sciences and Engineering Materials Science Metals and Alloys
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