Exchange bias in Fe and Ni codoped CuO nanocomposites

Exchange bias nanocomposites were obtained by the chemical concentration precipitation method, in which the ferrimagnetic MFe2O4 (M=Cu,Ni) particles were embedded in the antiferromagnetic (AFM) CuO matrix. The dependence of magnetization on temperature measurements show that the exchange bias effect in these composites is ascribed to the exchange coupling at the interface between the ferrimagnetic particles and spin-glass-like phase. With continuous introduction of magnetic Ni ions, the existence of domain state structure and the formation of soft magnetic phase in AFM matrix are responsible for the different behaviors of the exchange bias field and coercivity in these nanocomposites.