$Eu_xNi_{1-x}Fe_2O_4$, and $Tb_xNi_{1-x}Fe_2O_4$ where “x” varies as 0.02, 0.05, 0.1 two sets of series of samples have been prepared. The samples have been prepared by chemical co-precipitation route. For the first series, calculated amount of salt of Eu, Fe and Ni were dissolved in de-ionized water and stirred for a few minutes. 0.1 M (Molar) NH4OH solution was then slowly added drop wise under vigorous stirring. The alkali addition was continued till the pH of the solution was 10 and was left undisturbed for 1 hour for complete digestion. The precipitate was then washed thoroughly till pH 7 and then heated to 6000C. Next set of series prepared with same synthesis steps. The samples were checked for their phase purity by x ray diffraction which confirmed the spinel phase.