Effects of Nd3+ on the microstructure and magnetic properties of Ni-Zn ferrites

Ni0.4Zn0.6Fe2-xNdxO4(x = 0-0.07) ferrites doped with different amounts of Nd2O3 were prepared using standard ceramic technique. The samples were uniaxially pressed and sintered at 1250 degrees C for 4 h in air. The phase structure and microstructure of the samples were investigated using X-ray diffraction and scanning electron microscope, respectively. The complex permeability was measured using the impedance analyzer in the range of 1-100 MHz. The results indicate that with increasing Nd3+ content, the relative density and lattice parameter a of the sintered samples increase, whereas the real part of permeability (mu') and the magnetic loss tangent (tan delta) decrease. The substitution of Nd3+ for Fe3+ forms a secondary phase on the grain boundary of the matrix, which strongly restrains the grain growth of the matrix.