The structural modification upon milling in an intermediate step precursor
of the sol-gel method for BaFe12O19 hexaferrite BaM production is discussed
. The milling of the precursor diminishes the powder particle size, leads t
o a more homogeneous matrix and induces a solid-state transformation, from
gamma -Fe2O3 to alpha -Fe2O3. The induced modifications of the precursors c
hange the magnetic and structural properties of the final BaM hexaferrite c
ompared to the BaM obtained from the non-milled precursor.