Effect of Copper Oxide Addition on Dielectric and Magnetic Properties of Zn-Ti Substituted Sr-M Hexagonal Ferrite

Abstract

Sr-M-Hexagonal ferrite is an important ferrite for industrial application. Magnetic properties of the ferrite are usually improved by the substitution of Ti and Zn for iron in the hexagonal ferrite structure. In the present investigation, Zn and Ti have been substituted in the Sr-M-hexagonal ferrite as per the formula SrZn1.3Ti1.3Fe9.4O19. Effect of CuO sintering additives was investigated on the ferrite as per the composition SrZn1.3Ti1.3CuxFe9.4-xO19-z with x= 0.5 and 1.0. The ferrite has been synthesized through nitrate-citrate sol-gel combustion route. The decomposition behaviour of the gel has been investigated using DSC-TG analysis. The as burnt powder was finally calcined at 1200oC. The phase formation behaviour during calcination and after sintering has been investigated using X-ray powder diffraction analysis. Effect of CuO sintering additives on densification behaviour was investigated on the sintered pellet by measuring bulk density and apparent porosity. Similarly, its effect on the dielectric and magnetic properties of the ferrite has been investigated by measuring permittivity on pellet sample and magnetic permeability on torroid sample. The microstructural development of the ferrite was investigated using scanning electron microscope. Finally the changes in properties of the ferrite due to the addition of CuO have been explained and correlated. It has been found that the CuO addition was very effective for the phase formation and improved densification and hence improved magneto-dielectric properties of the ferrite.