Hgst Netherlands, B.v.

Western Digital Technologies, Inc.

Shun Tonooka

Masayoshi Shimizu

Kiwamu Tanahashi

Hiroyuki Nakagawa

Ichiro Tamai

Yoshinori Honda

Hiroyuki Katada

Reiko Arai

Maki Maeda

Miki Nishida

A magnetic media for magnetic data recording having reduced signal noise. The magnetic media includes a magnetic recording layer that has first, second and third portions. The first portion at the bottom of the magnetic recording layer includes an oxide and has a high anisotropy field. The third portion, located at the top of the magnetic recording layer has a low anisotropy field and does not include an oxide. The second portion, located between the first and third portions has an anisotropy field that is between that of the first and third magnetic portions. The second portion includes a thin layer of a material that has an extremely low anisotropy field that is located within a material having a higher magnetic anisotropy.

Perpendicular magnetic recording media having an extremely low Hk layer

A magnetic media having a lateral exchange control layer formed on a magnetic oxide layer of a magnetic recording layer. A cap layer is formed over the lateral exchange control layer. The lateral exchange control layer can be an alloy comprising Co and one or more of W, Ru, Hf, Ta, Nb and Fe. The lateral exchange control layer has the highest magnetic saturation moment among all the recording layers, and increases spacing between magnetic grains (e.g. increased non-magnetic boundary width), thereby reducing lateral exchange sigma. The presence of lateral exchange control increases signal to noise ratio and reduces bit error rate and increases areal density.

Perpendicular magnetic recording media with lateral exchange control layer

In one embodiment, a perpendicular magnetic recording medium includes: a substrate; and a soft magnetic underlayer structure positioned above the substrate, where the soft magnetic underlayer includes: a coupling layer; a first soft underlayer positioned above the coupling layer; and a second soft underlayer positioned below the coupling layer, where a difference between a magnetic flux density of the soft magnetic underlayer structure at 25&#xb0; C. and a magnetic flux density of the soft underlayer structure at 85&#xb0; C. is less than or equal to about 10% of the magnetic flux density of the soft magnetic underlayer structure at 25&#xb0; C.

Soft magnetic underlayer having high temperature robustness for high areal density perpendicular recording media

In one embodiment, a perpendicular magnetic recording medium includes an oxide recording layer including an oxide and a non-oxide recording layer which does not contain an oxide positioned above the oxide recording layer. The oxide recording layer includes a region Rwhere a grain boundary width in a direction parallel to a plane of formation of Rincreases therealong from a lowermost portion of the oxide recording layer toward a medium surface, a region Rpositioned above Rwherein a grain boundary width increases therealong toward the medium surface, a region Rwhere a grain boundary width of Rdecreases therealong from Rto R, with Rbeing positioned between Rand R, and a region Rwhere a grain boundary width of Rdecreases therealong from Rtoward the medium surface, with Rbeing positioned above Rand near an uppermost portion of the oxide recording layer.

Perpendicular magnetic recording medium with grain boundary controlling layers

In one general embodiment, a perpendicular magnetic recording medium includes a ferromagnetic granular layer with perpendicular magnetic anisotropy and having a granular structure; and a cap layer above said granular layer, the cap layer being a ferromagnetic continuous layer with perpendicular magnetic anisotropy, wherein, near a first side of said granular layer nearest the cap layer. Surfaces of the ferromagnetic grains of said granular layer facing the cap layer each have a domed shape defining undulations along the first side. Indentations in said ferromagnetic grains are filled by the oxide of the grain boundary in a vicinity of the first side of said granular layer. Undulations on a granular layer side of said cap layer are flatter than the undulations of the ferromagnetic grains on the first side of said granular layer.

Perpendicular magnetic recording media having a cap layer above a granular layer

According to one embodiment, a perpendicular magnetic recording medium includes at least one soft magnetic underlayer above a substrate, a seed layer above the at least one soft magnetic underlayer, an intermediate layer above the seed layer, a magnetic recording layer above the intermediate layer, and an overcoat layer above the magnetic recording layer, wherein the seed layer includes a second seed layer above a first seed layer. In another embodiment, the seed layer is a multilayered structure of at least two cycles of a unit of layered film which includes a first seed layer and a second seed layer. The first seed layer includes a non-magnetic alloy having a Face-Centered-Cubic (FCC) structure, and the second seed layer includes a soft magnetic alloy having a FCC structure. Other structures are also disclosed, according to more embodiments.

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Odawara, Japan

Shun Tonooka