Abstract: Magnetite powders are manufactured by first forming a precursor mixture containing iron atoms bonded to organic control agent molecules. Thereafter, magnetite is formed by (i) causing or allowing the iron atoms in the precursor mixture to form iron particles and (ii) reducing the iron atoms using a reducing agent. The magnetite powders obtained using the methods of the invention are superparamagnetic and can have very low densities. In one embodiment, the magnetite powders include a carbon coating on the magnetite particles which makes the particles resistant to being oxidized.

Abstract: The present invention provides a process for providing on the surface of a substrate an adherent phorphorous acid-based coating layer, the method comprising contacting said surface with a carrier conveying a coating composition comprising an acid selected from the group consisting of phosphoroic acids, organo-phosphoric acids, phosphonic acids, and mixtures thereof, at a sufficient temperature and for a sufficient time to bond at least a portion of the acid in the compositon to the oxide surface.