New Developments in Ferrite Plating

Abstract
The ferrite plating - a method synthesizing ferrite films from an aqueous solution - has developed lately as follows ; (1) Applying power ultrasound to aqueous solution improves the qualities of ferrite coating on polymer microspheres much, (2) similarity is found between mechanisms of the ferrite plating and bacterial Fe₃O₄ (magnetsome) synthesis, (3) using highly alkaline (pH=13) solution containing a chelating agent increases the solubilities of such particular ions as Mn²⁺ and Ba²⁺ in ferrite-plated films , and (4) Fe₃O₄/CdS multilayer films are synthesized from a wet chemical process. Applications are proposed of ferrite-plated films to (5) backlayers for CoCr perpendicular magnetic recording media, (6) contrast agents for ultrasonography, and (7) catalyst for decomposing aqueous residual chlorine.