  Thin hexagonal barium hexaferrite particles synthesized using the
microemulsion technique were studied. A water-in-oil reverse microemulsion
system with cetyltrimethylammonium bromide (CTAB) as a cationic surfactant,
n-butanol as a co-surfactant, n-hexanol as a continuous oil phase, and an
aqueous phase were used. The microstructural and magnetic properties were
investigated. The particles obtained were mono-domain with average particle
size 280 nm. The magnetic properties of the powder were investigated at 4.2 K
and at room temperature. The saturation magnetization was 48.86 emu/g and the
coercivity, 2.4 x 105 A/m at room temperature. The anisotropy field Ha and
magneto-crystalline anisotropy K1 were 1.4 x 106 A/m and 2.37 x 105 J/m3,
respectively.
