A Comparative Study of Magnetic Properties of Strontium Hexaferrite Prepared by Pure Chemicals and Its Natural Ore

摘要

In the present investigation strontium hexaferrite has been prepared from pure chemicals (strontium carbonate and iron oxide) and from natural ores of its derivatives (blue dust and upgraded celestite) by conventional calcination method. Two different batches of strontium hexaferrite have been prepared. The first batch was made with pure strontium carbonate and iron oxide powders and another from blue dust and strontium carbonate obtained from reduction of celestite. Strontium hexaferrite was prepared in mole ratio (Fe_2O_3/SrO) of 5.0, 5.3, 5.6, 5.9. For each batch effect of variation of mole ratio on the magnetic properties of strontium hexaferrites magnets have been studied. The study indicates that Br and BHmax value of pure chemicals based ferrite is maximum for mole ratio 5.6 whereas for ore based ferrite Br and BHmax values are maximum at mole ratio 5.0. The structural analysis indicate that these values are more because of formation of pure SrFe_(12)O_(19) phase that occurs at these mole ratios whereas for other mole ratios other phases also nucleate alongwith SrFe_(12)O_(19) phase.