Effect of calcium solubility on structural, microstructure and magnetic properties of SrFe12O19

The synthesis of Sr1-xCaxFe12O19 (x = 0.0-1.0 at increments of 0.1) samples is reported via a sol-gel auto combustion process. XRD data for Sr1-xCaxFe12O19 samples calcined at different temperatures indicates a) singlephase formation up to x = 0.20 in samples calcined at 900 ?degrees C, b) an increase in calcium solubility to 50 atomic % (x = 0.50) at 1200 ?degrees C, c) a decrease in lattice parameters and cell volume with increasing 'x' and d) the presence of segregated alpha-Fe2O3 phase for x > 0.50 at 1200 ?degrees C and for x & GE; 0.20 at 900 ?degrees C. As the maximum Ca solubility in SrM (SrFe12O19) phase has been observed at 1200 ?degrees C, most of the other characterizations have been performed on these samples only. An increase in grain size with 'x' was revealed in FESEM micrographs. Magnetic measurements show that in the x = 0.50 sample the maximum saturation magnetization (M-s) value is & AP;70.67 emu/g. Coercivity (Hc) decreases monotonically, with an increase in Ca content in SrM (SrFe12O19), from 3822 Oe (x = 0.00) to 2045 Oe (x = 0.50). Among the samples calcined at different temperatures, coercivity (Hc) decreases monotonically from 5650 Oe to 3128 Oe with an increased calcination temperature for samples of x = 0.20. The samples could be vital for magnetic recording and applications as permanent magnets due to their excellent magnetic properties.

Automated summary

The synthesis of Sr1-xCaxFe12O19 samples via a sol-gel auto combustion process is reported, and the samples' properties were characterized. It was found that single-phase formation occurred at low temperatures, and the lattice parameters and cell volume decreased with increasing Ca content. The samples exhibited excellent magnetic properties.