Nanoparticles of Ni(0.5-x)MnxZn0.5Fe2O4 with stoichiometric proportion, x = 0, 0.25, 0.35, 0.5, were prepared via the chemical co-precipitation process. The structure properties of nanoparticles were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Their magnetic properties were evaluated on a vibrating sample magnetometer ...