Hgst Netherlands, B.v.

Oleksandr Mosendz

Dieter Klaus Weller

Olav Hellwig

Hans Juergen Richter

Simone Pisana

Franck Rose

Qing Dai

James William Reiner

Jeffrey Scott Lille

Akemi Hirotsune

Hiroyuki Matsumoto

Xiaoping Bian

Ikuko Takekuma

Vijay P S Rawat

Run-Han Wang

Andrew Thomas McCallum

Shikha Jain

According to one embodiment, a magnetic recording medium includes: a substrate, a seed layer positioned above the substrate, and a magnetic recording layer structure positioned above the seed layer. The magnetic recording layer structure includes: a first magnetic recording layer having a plurality of FePtCu magnetic grains and a first segregant, and a second magnetic recording layer positioned above the first magnetic recording layer, the second magnetic recording layer having a plurality of FePt magnetic grains and a second segregant, where a Curie temperature of the first magnetic recording layer is lower than a Curie temperature of the second magnetic recording layer.

Heat assisted magnetic recording (HAMR) media having a highly ordered crystalline structure

A magnetic medium for perpendicular magnetic data recording having improved corrosion characteristics and reduced surface roughness. The magnetic medium includes an under-layer and a perpendicular magnetic recording layer formed over the under-layer. The under-layer can be formed of MgO and has an oxygen concentration that is greater at the perpendicular magnetic recording layer than it is away from the perpendicular magnetic recording layer.

Perpendicular magnetic recording media having novel magnetic under-layer structure

According to one embodiment, a magnetic medium includes a plasmonic underlayer having an Au alloy, where the Au alloy includes one or more alloying components that are substantially immiscible in Au; and a magnetic recording layer above the plasmonic underlayer. According to another embodiment, a magnetic medium, includes a multilayered plasmonic underlayer; and a magnetic recording layer above the multilayered plasmonic underlayer.

Thermally stable Au alloys as a heat diffusion and plasmonic underlayer for heat-assisted magnetic recording (HAMR) media

A method for etching a media is disclosed. A first magnetic layer comprising grains is deposited with a segregant such that a portion of the first segregant covers a top surface of the grains of the first magnetic layer and a second portion of the first segregant separates the grains of the first magnetic layer. The first segregant is etched to remove the portion of the first segregant that covers the top surface of the grains.

Media etch process

In one embodiment, a magnetic media suitable for HAMR recording includes a recording layer having first and second magnetic layers. The first magnetic layer has a first segregant between magnetic grains thereof, the first segregant being primarily C. Moreover, the second magnetic layer is formed above the first magnetic layer. The second magnetic layer has a second segregant between magnetic grains thereof, the second segregant being primarily C and a second component. Additional systems and methods are also described herein.

Dual segregant heat assisted magnetic recording (HAMR) media

An 'all optical switching' (AOS) magnetic recording system, i.e., one that does not require a magnetic field to reverse the magnetization in the magnetic recording media, uses a FeMnPt L1alloy as the magnetic media. A FeMnPt alloy, with appropriate amounts of Mn, will have high magneto-crystalline anisotropy, but also ferrimagnetic spin alignment for triggering AOS. The combination of high magneto-crystalline anisotropy and ferrimagnetic spin configuration enables the FeMnPt media to function as magnetic media whose magnetization can be switched solely by polarized laser pulses. The FeMnPt media for may be a single layer with or without any segregants. Alternatively, the FeMnPt media may be a multilayered recording layer comprising alternating layers of FePt and MnPt L1ordered alloys. The segregant-free embodiments of the FeMnPt material may be patterned to form bit-patterned-media (BPM).

All-optical magnetic recording system using FeMnPt media

A vacuum planarization method substantially improves the surface roughness of a thermally-assisted recording (TAR) disk that has a recording layer (RL) formed of a substantially chemically-ordered FePt alloy or FePt-X alloy (or CoPt alloy or CoPt-X alloy) and a segregant, like SiO. A first amorphous carbon overcoat (OC) is deposited on the RL and etched with a non-chemically reactive plasma to remove at least one-half the thickness of OC. Then a second amorphous carbon overcoat (OC) is deposited on the etched OC. The OCis then reactive-ion-etched, for example in a H/Ar plasma, to remove at least one-half the thickness of OC. A thin third overcoat (OC) may be deposited on the etched OC

Method for planarizing a perpendicular magnetic recording disk for thermally-assisted recording (TAR)

A heat enabled magnetic media having a composite magnetic recording layer structure that includes first and second magnetic layers and an exchange coupling layer sandwiched between the first and second magnetic layers. The exchange coupling layer has a reduced Curie temperature that allows the magnetic layers to become decoupled a lower temperature. This reduced Curie temperature can be achieved the addition of an alloying element such as Ni or Cu into the exchange coupling layer. Therefore, the exchange coupling layer can be constructed of an alloy such as FePtNi FePtCu, and the magnetic layers can be constructed of a material such as FePt.

Thermally enabled exchange coupled media for magnetic data recording

A method of making a thermally-assisted recording (TAR) disk includes etching an initial layer of generally spherically shaped FePt grains encapsulated by shells of graphitic carbon layers. The etching partially or completely removes the carbon layers on the tops of the shells, exposing the FePt grains while leaving carbon segregant material between the FePt grains. Additional Fe, Pt and C are then simultaneously deposited. The additional Fe and Pt grow on the exposed FePt grains and increase the vertical height of the grains, resulting in growth of columnar FePt grains. The additional C forms on top of the grains that together with the intergranular carbon form larger carbon shells. The resulting FePt grains thus have a generally columnar shape with perpendicular magnetic anisotropy, rather than a generally spherical shape. Lateral grain isolation is maintained by the carbon segregant remaining between the grains.

Method for making a perpendicular thermally-assisted recording (TAR) magnetic recording disk having a carbon segregant

A method for making a bit-patterned-media (BPM) magnetic recording disk includes depositing a FePt (or CoPt) alloy recording layer, and then depositing a sealing layer on the FePt layer before high-temperature annealing. The high-temperature annealing causes the FePt to become substantially chemically-ordered in the L1phase. After annealing, the sealing layer is removed. The sealing layer prevents nanoclustering and agglomeration of the FePt material at the surface of the FePt layer and the sealing layer, which would result in undesirable high surface roughness of the FePt, making patterning of the FePt layer difficult. The FePt layer can be patterned into the discrete islands for the BPM disk either before deposition of the sealing layer or after deposition and removal of the sealing layer. After patterning and removal of the sealing layer, the disk protective overcoat is deposited over the discrete data islands.

Growing community of inventors

San Jose, CA, United States of America

Oleksandr Mosendz