Magnetic properties of La-substituted Ni–Zn–Cr ferrites via rheological phase synthesis

Nanocrystalline ferrites Ni0.6Zn0.4Cr0.5LaxFe1.5−xO4 (x = 0–0.10) were prepared by a rheological phase-reaction process. The influence of the La content on microstructure and magnetic properties of samples were investigated. The structure, morphology and magnetic properties of the obtained products were characterized by X-ray diffractometer (XRD), transmission electron microscope (TEM), vibrating sample magnetometer (VSM) and network analyzer (NA). XRD results showed that the substituting La3+ ions had a solubility limit in the spinel lattice. The present work showed that the crystallite size and magnetic properties could be tuned over by introducing La3+ ions into the Ni–Zn–Cr ferrites. The crystallite size, saturation magnetization of samples decreased with the increase of La content, whereas the variation of coercivity was reverse. Moreover, the microwave absorption ability of the samples can be improved by changing the components of the ferrites.