Nanocrystalline Magnetite: Synthetic Crystallite Size Control and Resulting Magnetic and Electrochemical Properties

A synthetic strategy for magnetite crystallite size control is reported, along with the detailed characterization and electrochemical measurements of samples of varying crystallite sizes. Nanocrystalline is prepared by coprecipitation induced by triethylamine from aqueous iron(II) and iron(III) chloride solutions of varying concentrations. Variation of the iron(II) and iron(III) concentrations results in crystallite size control of the products. Materials characterization of the samples is reported, including X-ray diffraction, transmission electron microscopy, particle size, and saturation magnetization results. A strong correlation between discharge capacity and voltage recovery behavior vs magnetite crystallite size was observed when tested as an electrode material in lithium electrochemical cells.