SYSTEMS AND METHODS FOR MAKING RADIALLY ANISOTROPIC THIN-FILM MAGNETIC TORROIDAL CORES, AND RADIALLY ANISOTROPIC CORES HAVING RADIAL ANISOTROPY, AND INDUCTORS HAVING RADIALLY ANIOSOTROPIC CORES

摘要

A radially anisotropic toroidal magnetic core is fabricated by a method including providing apparatus having a first magnet for providing a radial magnetic field extending across a cavity from an axial spindle to a surrounding second magnetic element, placing a substrate in the cavity, the substrate having a hole fitting around the head of the spindle; and sputter-depositing a film of ferromagnetic material onto the substrate. An alternative fabrication uses a similar fixture to impose magnetic anisotropy by annealing a previously-formed toroidal core. A particular fixture adapted for deposition by electroplating or for applying anisotropy by annealing pre-formed cores applies magnetic fields symmetrically from above and below the cores. Also described are the radially anisotropic core produced by the method, and an inductor having a coil wound on the radially anisotropic core.