Dislocation etching of flux grown strontium hexaferrite single crystals (abstract)

Hexagonal hard ferrites like SrFe12O19 are technically interesting materials not only because they are the traditional permanent magnets but also as emerging magnetic recording media and as potential magneto‐optic devices. For these reasons the study of dislocations in these samples is quite significant. Flux grown single crystals of SrFe12O19 are etched in 37% HNO3 at 100 °C and 85% H3P4 at 120 °C. These two etchants produce hexagonal pits on (001) planes that are established as dislocation etchants by performing the following experiments: (1) successive etching for prolonged periods resulting in persistent point bottomed etch pits at all the stages; (2) etching of matched (0001) cleavages in similar, as well as dissimilar, etchants which produce 1:1 corresponding point bottomed etch pits on a pair of the matched cleavages; (3) etching of low angle grain boundaries which consist of a grid of equally spaced edge dislocations. An equally spaced row of etch pits is obtained along the grain boundaries. Hexag...