Dark Field Observation of Fe3O4-γFe2O3 Multiphase Films

Y. Yamazaki , T. Namikawa , Y. Koizumi , S. Meguro

We investigated the phase separation of cubic and tetragonal systems in Fe3O4-γFe2O3 intermediate thin films. An Fe thin film of 50 nm was deposited on a SiO2 substrate using an electron beam evaporator at room temperature. The film was oxidized to αFe2O3 at 400°C in air, then the film was reduced to Fe3O4 at 320°C in methanol vapor. The gradual oxidation of the Fe3O4 film to γFe2O3 film at 240°C was terminated when the coercive force of the film increased more than 1000 Oe at an intermediate state. The intermediate film was examined by dark-field TEM observation with tetragonal diffraction spots. The result revealed that crystallites of about 10 nm of tetragonal structure are distributed in a matrix of cubic phase.

Domaines: Articles anciens

Y. Yamazaki, T. Namikawa, Y. Koizumi, S. Meguro. Dark Field Observation of Fe3O4-γFe2O3 Multiphase Films. Journal de Physique IV Proceedings, 1997, 07 (C1), pp.C1-599-C1-600. ⟨10.1051/jp4:19971247⟩. ⟨jpa-00254933⟩