Effect of sintering temperature on the structural, electrical and magnetic properties of Li0.5Al1.0Fe2O4 ferrite prepared by combustion method

Al3+ substituted lithium ferrite of S-type having chemical formula Li0.5Fe1.5Al1.0O4 was successfully synthesized by the combustion method. The ferrite was then divided into two parts and sintered at two different temperatures, respectively to study the effect on its properties. It was found that at lower sintering temperature the particle size of product was reduced. This was clearly indicated by the broadening of major peaks of X-ray diffraction pattern. Corresponding increase in activation energy and decrease in coercivity and retentivity were also observed during electrical and magnetic studies. The part of compound sintered at lower temperature was judged as admixture of single domain and superparamagnetic particles. The micrographs of the compound supported this judgment.