Modulation of physico-chemical, magnetic, microwave and electromagnetic properties of nanocrystalline strontium hexaferrite by Co-Zr doping synthesized using citrate precursor sol-gel method

Co-Zr doped SrCor,Fe(12-2x) O-19 (x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) have been synthesized by citrate precursor sol-gel method. We have studied the impact of coupled substitution of magnetic Co2+ and non-magnetic Zr4+ for Fe3+ on the morphology, magnetic, microwave and electromagnetic properties of SrCoxZrx Fe(12-2x) O-19. Characterization of these materials has been done by XRD, FT-IR, EDS, TEM, VSM and Mossbauer spectroscopy techniques. Complex permeability (mu'), complex permittivity (epsilon') and reflection loss curves have also been analyzed. XRD analysis indicates the formation of single phase hexagonal ferrites at a low temperature of 800 degrees C. Mossbauer spectra indicates that the dopant ions are located on the tetrahedral 4f(1) and octahedral 4f(2) sites up to x=0.4, octahedral 12k site and bipyramidal 2b site for x=0.6 and 12k site for x=0.8-1.0. The reflection loss (R.L.) analysis shows that all the ferrites (except x=0.2) have wide absorption bandwidth (R.L. < -10 dB for 2-3.5 GHz) with peaks of 90-99% absorption in 12.4-18 GHz band.