Microstructure and magnetic microstructure of La plus Co doped strontium hexaferrites

After being cut, carefully ground, meticulously polished and properly eroded, the microstructure and magnetic microstructure of La(0.3)Sr(0.7)Fe(11.8)Co(0.2)O(19) hexaferrites were investigated by using magnetic force microscopy. The shapes of a large amount of the La(0.3)Sr(0.7)Fe(11.8)Co(0.2)O(19) grains were determined to be mostly irregular flat columns. The shape anisotropy of the hexaferrite grains can be explained by an abnormal grain growth process occurs for La + Co-containing hexaferrite powders. The magnetizations mainly align parallel or anti-parallel to the direction of oriented magnetic field. The magnetic domain sizes are in the same order of magnitude with the grain sizes. No complex domain structures like corrugation and spike were observed. Micromagnetic simulations were also performed to help analyzing the magnetic microstructure. (c) 2009 Elsevier B.V. All rights reserved.