Undercoating for perpendicularly magnetized film, perpendicularly magnetized film structure, perpendicular mtj element, and perpendicular magnetic recording medium using same

Disclosed is a perpendicularly magnetized film structure employing a highly heat resistant undercoating film on which a cubic or tetragonal perpendicularly magnetized film can grow with high quality, said structure comprising: a cubic monocrystalline substrate (5) having a (001) plane direction, or a substrate (5) having a cubic alignment film that has grown with a (001) plane direction; an undercoating layer (6) made of a thin film of metal, such as Ru or Re, having an hcp structure and formed on said substrate (5), wherein the [0001] direction of the thin metal film forms an angle within a range from 42° to 54° with respect to the direction or the (001) plane direction of the substrate (5); and a perpendicularly magnetized layer (7) located on the metal undercoating layer (6), and made of a cubic material that has grown with a (001) plane direction, the composition material of the cubic material being selected from the group consisting of Co-based Heusler alloys, bcc-structure cobalt-iron (CoFe) alloys, and the like.