M. Ishaque

MAGNETIC PROPERTIES OF CO-PRECIPITATED MnZn FERRITE-SiO2 COMPOSITES

A series of composite ferrites with chemical formula (1–x)[Mn0.5Zn0.5Fe2O4]·x[SiO2](x = 0.0, 0.20, 0.30, 0.40, 0.50) were prepared by the co-precipitation technique. The samples were finally sintered at 1150°C followed by air quenching. The x-ray diffraction analysis confirms the phases precipitated out in the samples. AC magnetic susceptibility of these samples has been measured using the low field mutual inductance technique over the temperature range 298 K to 550 K at a frequency of 250 Hz. The magnetic parameters like Curie constant, C, Curie temperature, Tc, Lande splitting factor, g, effective magnetic moment, Peff, exchange integral, J/kB, and characteristic temperature, θ(K) were calculated. The reciprocal of susceptibility versus temperature curves of each sample follows the Curie Weiss behaviour above the Curie temperature. Below the Curie temperature, all the samples show the ferrimagnetic behaviour. It was concluded that the magnetic properties were enhanced by the addition of silicon as is evident by the variation of magnetic interactions J, with Si-concentration and followed subsequently by the Peff, θ(K) and Tc etc.