Nano ferrites, especially spinel ferrites have evoked greater attention in the recent years because of their potential in technological applications. Properties of nano ferrites could be tailored and improved by the incorporation of suitable divalent, trivalent or tetravalent impurities into the spinel lattice. Hence the investigation on the properties of substituted nano ferrites helps to improve the performance of these materials and make their applications more diverse. This work gives an overview of the structural, morphological, magnetic and dielectric properties of spinel ferrites nanoparticles. Copper-aluminum was substituted into the spinel cobalt ferrite lattice and the resulting changes in properties were analyzed.