Impact of Zn2+-Zr4+ substitution on M-type Barium Strontium Hexaferrite's structural, surface morphology, dielectric and magnetic properties

We report the synthesis of Ba0.5Sr0.5ZnxZrxFe12-2xO19 (x = 0.00-1.00) samples using sol-gel auto combustion method. The Rietveld refinement of XRD data indicates a) pure phase formation, b) increase in lattice parameters with composition and c) the absence of undesirable phases such as alpha-Fe2O3, BaCO3 and SrCO3. FESEM and TEM micrographs reveal an increase in grain size with 'x'. The broadening of Raman peaks without any peak shift in all the samples indicates that the Zn2+/Zr4+ ions are incorporated into Ba0.5Sr0.5Fe12O19 without altering the local structure. Magnetic measurements reveal that the maximum value of saturation magnetization (M-s) is 67.37 emu/g in x = 0.4 sample. The coercivity (H-c) monotonically decreases from 4.936 KOe to 1.029 KOe with increasing concentration of non-magnetic dopants. The dielectric constant values decreases monotonically as function of frequency for all the samples. The samples because of their superior magnetic properties could be vital for high density perpendicular recording, high density parallel recording EM shielding and permanent magnet applications.

Automated summary

A sol-gel auto combustion method was used to synthesize Ba0.5Sr0.5ZnxZrxFe12-2xO19 (x = 0.00-1.00) samples, with XRD data showing pure phase formation and an increase in lattice parameters with composition. Magnetic measurements indicated a decrease in coercivity with the increasing concentration of non-magnetic dopants, while the saturation magnetization peaked at x = 0.4 sample.