بر تركيب فازي پودرهاي باريم هگزافريت تهيه شده به روش سل - ژل احتراقي HP اثر عامل تنظيم كننده

Influence of pH Adjusting Agent on the Characteristics of Ba-Hexaferrite Particles Prepared by Sol-Gel Combustion Method

Nano-crystalline particles of baruim hexaferrite (BaFe12O19) have been prepared by a sol-gel combustion technique using nitrate-citrate gels. Ammonia and sodium hydroxide were used as adjusting agents. The results revealed that the nitrate-citrate gels in both cases exhibit a self-propagating behavior after ignition. The thermal decomposition process of the nitrate citrate gels and as-burnt powders was investigated by XRD and DTAJTG techniques. The results indicated that the single phase of Ba-hexaferrite forms at a relatively low temperature of 900°C when ammonia is used as a pH adjusting agent. Also, the SEM investigations and VSM measurements revealed that the barium hexaferrite particles processed in the presence of ammonia exhibit a larger mean particle size and higher magnetic properties in comparison with those of processed using sodium hydroxide.