MAGNETICALLY ANISOTROPIC BINDER-FREE FILMS CONTAINING DISCRETE HEXAFERRITE NANOPLATELETS

Some variations provide a magnetically anisotropic structure comprising a hexaferrite film disposed on a substrate, wherein the hexaferrite film contains a plurality of discrete and aligned magnetic hexaferrite particles, wherein the hexaferrite film is characterized by an average film thickness from about 1 micron to about 500 microns, and wherein the hexaferrite film contains less than 2 wt % organic matter. The hexaferrite film does not require a binder. Discrete particles are not sintered or annealed together because the maximum processing temperature to fabricate the structure is 500° C. or less, such as 250° C. or less. The magnetic hexaferrite particles may contain barium hexaferrite (BaFe12O19) and/or strontium hexaferrite (SrFe12O19). The hexaferrite film may be characterized by a remanence-to-saturation magnetization ratio of at least 0.7. Methods of making and using the magnetically anisotropic structure are also described.