NOVEL SYNTHESIS AND PROPERTIES OF SPINEL FERRITE FOR MAGNETOOPTIC RECORDING AND RE-RECORDING

Cobalt ferrite spinels films have been synthesized by oxidizing at dif ferent temperatures of a metallic alloy film CoFe2. This metallic film is deposited on glass substrates by sputtering of a Fe target covered by Co platelets. X ray diffraction data and electron microprobe analy sis show that the spinel phase CoFeO4 begins to form at 300-degrees-C and crystallizes at higher temperatures. No preferential orientation w as observed on glass substrates. Magnetic and magneto-optic properties (Faraday rotation (FR)) are a function of the oxidizing temperature T (ox) and particularly at 632.8 nm, FR are strongly related to the dist ribution of the Co2+ ions in the different sites of the spinel structu re. Films prepared at T(ox) > 600-degrees-C present properties close t o those of bulk CoFeO4. The high FR of the films indicate that this me thod could be used to synthesize Co ferrite spinel derived compounds a s MO recording media.