One of current magnetization recording methods which are generally adopted is an in-plane magnetization recording method used for coated and deposited-type magnetic recording media. This method involves magnetizing an information to be recorded in an in-plane direction in a plane on the surface of a magnetic recording medium by a magnetic head to record it, but has a limit in recording density in principle because of the magnetization recording in a plane.
On the other hand, there has been extensive development of a perpendicular magnetization recording method which enables the increase in recording density in principle. This method is contemplated to enable the recording with a ultra-high density by the combination of an vertical head with a medium having a perpendicular magnetic anisotropy, and recently, the applications thereof are not only to floppy disks but also to hard disks.
Representive magnetic thin films as a recording medium for use in the above perpendicular magnetization recording method include thin films of a Co-Cr based alloy and Ba ferrite. However, the former thin film of a Co-Cr alloy is accompanied by problems of a wear resistance and an expensiveness because it contains Co and Cr which are a relatively expensive element, respectively, and of an unstability in the supply of these elements as starting materials. On the other hand, with the thin film of Ba ferrite, thin film making conditions are severe in the production of a crystal having a high orientation closely associated with a perpendicular magnetic anisotropy, and it is necessary to heat a substrate to a temperature of 500.degree. C. or more, resulting in a complicated procedure, a limited type of substrate material and an impossibility of using an inexpensive resinous substrate such as PET.
In this way, it is the existing circumstance that the thin films of Co-Cr based alloy and Ba ferrite have a number of industrial problems for recording media and that a novel material recording medium is strongly desired.