Underlayer for perpendicularly magnetized film, perpendicularly magnetized film structure, perpendicular MTJ element, and perpendicular magnetic recording medium using the same

A perpendicular MTJ element film comprising:

• any one of a cubic single crystal substrate having a (001) plane, or a substrate having a cubic oriented film grown to have a (001) plane;
• an underlayer formed on the substrate and formed from a metal thin film having an hcp structure, in which a [0001] direction of the metal forms an angle in the range of 42° to 54° with respect to the <001> direction or the (001) plane of the substrate;
• a first perpendicularly magnetized layer located on the metal underlayer and formed from a cubic crystal material as a constituent material selected from the group consisting of a Co-based Heusler alloy, a cobalt-iron (CoFe) alloy having a bcc structure, an L10-based alloy XY, wherein X is Fe or Co and Y is Pt or Pd, a DO22 type manganese alloy, and an L10 type manganese alloy, and grown in the (001) orientation;
• a tunnel barrier layer located on the first perpendicularly magnetized layer and containing a constituent material selected from the group consisting of MgO, spinel (MgAl2O4), and aluminum oxide (Al2O3), and grown in the (001) orientation and a direction equivalent thereto;
• and
• a second perpendicularly magnetized layer located on the tunnel barrier layer and formed from a cubic material selected from the group consisting of a Co-based Heusler alloy, a cobalt-iron (CoFe) alloy having a bcc structure, an L10-based alloy XY, wherein X is Fe or Co and Y is Pt or Pd, a DO22 type manganese alloy, and an L10 type manganese alloy, and grown in the (001) orientation.