a magnetically anisotropic magnet substrate is coated with at least one layer of nickel plating followed by a chromate layer . the chromate top layer improves the corrosion resistance of the coated magnet substrate . in a preferred embodiment , the layer of nickel plating includes a first layer of a non - bright nickel plating followed by a second layer of a semi - bright nickel plating . one embodiment adds a copper under - layer below the nickel plating .