Ferrite compositions, particularly ferrite coated substrates and more particularly fiber plys coated with ferrites in fiber reinforced polymer composites (FRPC), and composites with a plurality of functionalized fiber layers, include a magnetic ferrite composition for coating a substrate, said composition comprising a resin, and dispersed therein ferrite particulates, wherein said ferrite particulates have an average longest dimension of less than 500 nm. The composition may be used to provide a ferrite composite structure comprising at least one fiber ply, with at least one layer of a magnetic ferrite composition deposed thereon, wherein said ply is substantially encapsulated in a binder matrix to form a fiber reinforced polymer composite.