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Synthesis and properties of precipitated cobalt ferrite nanoparticles

The formation and properties of cobalt ferrite were investigated with XRD, FT-IR, FE-SEM, Mossbauer and magnetometry. Cobalt ferrite samples were prepared (a) by combining coprecipitation Co(OH)2/2Fe(OH)3, using NaOH between pH 5.2 and 11.4 and autoclaving, and (b) by autoclaving the Co(OH)2/2Fe(OH)3 coprecipitate in a very strong alkaline medium. XRD and FE SEM showed that both CoFe2O4 crystallites and particles were in the nanosize range. The FT-IR spectra were typical of spinel ferrites. Cobalt ferrite precipitated at pH 7.2 and at 11.4 contained a small fraction of a- Fe2O3, whereas in the sample precipitated at pH 11.4 a very small amount (traces) of a-FeOOH were detected by FT-IR, additionally. Parameters obtained by Mossbauer spectroscopy suggested a structural migration of cobalt and iron ions in prepared cobalt ferrite spinels with the prolonged time of autoclaving. Magnetic measurements showed the magnetic behaviour typical of spinel ferrite nanoparticles.

Cobalt ferrite ; XRD ; FT-IR ; FE SEM ; Mossbauer ; Magnetic measurements

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