National Institute for Materials Science

Jungwoo Koo

Kazuhiro Hono

Hiroaki Sukegawa

Seiji Mitani

Tadakatsu Ohkubo

Takao Furubayashi

Koichiro Inomata

Jason Paul Hadorn

Zhenchao Wen

Disclosed is a perpendicularly magnetized film structure using a highly heat resistant underlayer film on which a cubic or tetragonal perpendicularly magnetized film can grow, comprising a substrate of a cubic single crystal substrate having a (001) plane or a substrate having a cubic oriented film that grows to have the (001) plane; an underlayer formed on the substrate from a thin film of a metal having an hcp structure in which the [0001] direction of the thin metal film forms an angle in the range of 42&#xb0; to 54&#xb0; with respect to the &#x3c;001&#x3e; direction or the (001) orientation of the substrate; and a perpendicularly magnetized layer located on the metal underlayer and formed from a cubic material selected from a Co-based Heusler alloy and a cobalt-iron (CoFe) alloy having a bcc structure a constituent material, and grown to have the (001) plane.

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

Disclosed is a perpendicularly magnetized film structure that uses a highly heat resistant underlayer film on which a cubic or tetragonal perpendicularly magnetized film can grow with high quality, the structure comprising any one substrate () of a cubic single crystal substrate having a (001) plane, or a substrate having a cubic oriented film that grows to have the (001) plane; an underlayer () formed on the substrate () from a thin film of a metal having an hcp structure, such as Ru or Re, in which the [0001] direction of the thin metal film forms an angle in the range of 42&#xb0; to 54&#xb0; with respect to the &#x3c;001&#x3e; direction or the (001) orientation of the substrate (); and a perpendicularly magnetized layer () located on the metal underlayer () 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, and the like, as a constituent material, and grown to have the (001) plane.

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Ibaraki, Japan

Jungwoo Koo