X-ray and magnetic properties of manganese substituted Ni-Zn ferrites

Ni_0.35 Zn_065-x Mn_x Fe₂ O ₄ ferrite system with x varies from 0.00 to 0.25 in steps of 0.05 has been prepared by conventional ceramic technique. The samples were sintered at 1250 °C for 4 hours in air atmosphere followed by natural cooling. X-ray diffraction patterns of all the samples exhibit all the major peaks concerned to the cubic spinel structure. Lattice constants were estimated using high angle x-ray peaks. The variation of lattice constant with manganese concentration follows the similar trend as that of percent porosity. Though the manganese ions with 5 μB are substituted in place of non-magnetic zinc ions, the saturation magnetization of the system is recorded a continuous increase through out the range of substitutions. Curie temperature of the system is also found to increase from 266 °C (x=0.00) to 372 °C (x=0.25) with the increase in manganese content. Smooth coercivity variation suggests better structural homogeneity. The results are discussed in light of the distribution of magnetic cations.