Structural and Magnetic Studies of SrFe12O19 by Sol-gel Method

Strontium hexaferrite (SrFe12O19) particles were prepared by sol gel method at two different calcination temperatures, namely, at 800 °C and 1000 °C. It was found that SrFe12O19 prepared, at 800 °C showed a mixture of Fe2O3 co-existed while at a higher temperature of 1000 °C, no other oxide impurities was detected. Superconducting quantum interference device (SQUID) was performed on both the sol-gel prepared samples. The coercivity for the low temperature prepared SrFe12O19 showed a much higher value of 6250 Oe compared with the high temperature prepared SrFe12O19 which was only 4500 Oe. In addition to the calcination temperature, the presence of Fe2O3 also affected the coercivity of the hexaferrite particles. Thermogravimetric analysis (TGA) was performed at 950 °C on both the sol-gel samples and it was noted that the low temperature prepared SrFe12O19 has a higher weight loss about 3.2% compared to the high temperature sample which has a much smaller weight loss of only 0.6%. The high weight loss was attributed by the breakdown of Fe2O3.