Magnetic code disc film and preparation method thereof, and magnetic encoder

The invention relates to the technical field of magnetic materials. The invention provides a magnetic code disc film, a preparation method thereof and a magnetic encoder. The magnetic code disc thin film comprises a [SrFe12O19 film/Co film] n multi-period ferrite thin film located on the surface of a substrate, a conventional ferrite block is replaced, the magnetic domain of the thin film is very uniform within the nanoscale range, and higher density can be written in when signals are written in; compared with a traditional SrFe12O19 film, according to the magnetic code disc film, the Co film is introduced to serve as a periodic intercalation layer, and the residual magnetism of the film can be greatly improved (the residual magnetism is improved from about 2500 Oe before the Co film layer is introduced to about 3700 Oe after the Co film intercalation layer is introduced; and the saturation magnetization intensity is improved from about 3000Oe before the Co film layer is introduced to about 5200Oe after the C