Study of the effect of additives on magnetic and dielectric properties of M-type Sr-hexaferrites

Magnetic and dielectric properties of M-type Sr-hexaferrites of composition (SrO) 1-x (La2O3) x 5.7 Fe2O3, where x= 0.00, 0.04, 0.08 and SrO. 5.7 Fe2O3+[0.7 wt% CaO+ 0.3 wt% SiO2] prepared by conventional ceramic technology at different sintering temperatures using magnetite of Cox’s Bazar beach sand, Bangladesh have been investigated in the present work. The permeability, loss factor, quality factor and dielectric constant measurements have been carried out on various samples of Sr-hexaferrites with the addition of La2O3, CaO and SiO2. The magnetic and dielectric properties of Sr-hexaferrites have been found to be strongly dependent upon the additives, temperature and frequency. Throughout the frequency range investigated up to 500 KHz the permeability has been found to be almost constant ie independent of frequency. No relaxation or resonance has been observed. Dielectric constant decreases with increasing frequency exhibiting normal dielectric behavior of ferrite