Comparison between Powders of Strontium Hexaferrite Processed by Dynamic Gas Heat Treatment and Re-Calcination

The utilization of classical ceramic technology for ferrite preparation permits to obtain strontium hexaferrite with big crystals, of micrometer size, with a smaller coercive force than the hexaferrite with submicron crystals. In this work the strontium hexaferrite was obtained with submicron crystals, by hot reduction of the hexaferrite obtained through ceramic technology in CO atmosphere, followed by the thermal re-oxidization in air. The effects of treatment in CO atmosphere and of the re-calcination treatment on the magnetic and electric properties of the strontium hexaferrite were investigated.