Hydrothermal Synthesis of Ba‐Hexaferrite Nanoparticles

Barium hexaferrite BaFe 12 O 19 nanoparticles with a single‐domain size were synthesized using a controlled hydrothermal process involving the LaMer–Dinger principle and the Ostwald ripening mechanism. Nanocrystalline particles of BaFe 12 O 19 were obtained when the molar ratio of the precursor composition Ba(OH) 2 ·8H 2 O/γ‐Fe 2 O 3 was 0.3 and the concentration of the suspension was about 1 wt%. The as‐synthesized crystalline BaFe 12 O 19 platelets approximately 50 nm in length and 5 nm in thickness exhibited a saturation magnetization of 40 Am 2 /kg.