Heat-assisted magnetic recording (HAMR) media status, requirements, and challenges to extend the areal density (AD) of magnetic hard disk drives beyond current records of around 14 Tb/in2 are updated The structural properties of granular high anisotropy chemically ordered L10 FePtX-Y HAMR media by now are similar to perpendicular CoCrPt-based magnetic recording media Reasonable average grain diameter ⟨D⟩ = 8–10 nm and distributions σD/D ∼ 18% are possible despite elevated growth temperatures TG = 650–670 °C A 2× reduction of ⟨D⟩ down to 4–5 nm and lowering σD/D < 10%–15% are ongoing efforts to increase AD to ∼4 Tb/in2 X = Cu ∼ 10 at % reduces the Curie temperature TC by ∼100 K below TC,bulk = 750 K, thereby lowering the write head heat energy requirement Multiple FePtX-Y granular layers with Y = 30–35 vol % grain-to-grain segregants like carbides, oxides, and/or nitrides are used to fully exchange decouple the grains and achieve cylindrical shape FePt is typically grown on fcc MgO (100) seedlay

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Review Article: FePt heat assisted magnetic recording media

Heat-assisted magnetic recording (HAMR) is being developed as the next generation magnetic recording technology. Critical components of this technology, such as plasmonic near-field transducer (NFT) and high anisotropy granular FePt media, as well as the performance and reliability of fully integrated drives have been reported. This paper will focus on the progress and challenges of HAMR media, including microstructure and thermal design as well as the testing and characterization at high field and high temperature. Due to the importance of the Curie temperature distribution, $\sigma T_{C}$ , for HAMR, we present a newly developed temperature-dependent complex ac susceptibility method to extract $\sigma T_{C}$ for HAMR media. Such novel magnetic characterization methods have been used in combination with other high field magnetic metrology and spin-stand recording to provide feedback for continuous improvements of HAMR media. Together with NFT and write head design, the thermal design, $\sigma T_{C}$ , and microstructure of the media are key factors to reduce the transition jitter below 2 nm as demonstrated in a previously reported 1 Tb/in2 HAMR demonstration. Here, we report the further improvements by significantly enabling higher linear density (>2500 kfci) HAMR and steady progress in areal density to 1.402 Tb/in2.

High Density Heat-Assisted Magnetic Recording Media and Advanced Characterization—Progress and Challenges

Various embodiments provide for a heat assisted magnetic recording (HAMR) media comprising: a magnetic recording layer; a barrier layer disposed under the magnetic recording layer; a first underlayer disposed under the barrier layer; and an amorphous seedlayer disposed under the first underlayer. For some embodiments, the recording medium may comprise: a magnetic recording layer including FePt alloy, a CoPt alloy, or a FePd alloy; a barrier layer including MgO, TiC, TiN, CrN, TiCN, β-WC, TaC, HfC, ZrC, VC, NbC, or NiO; a first underlayer including RuAl-oxide, NiAl, FeAl, AlMn, CuBe, or AlRe; or an amorphous seedlayer including a Cr—X alloy, where X comprises Al, B, C, Cu, Hf, Ho, Mn, Mo, Ni, Ta, Ti, V, W, or Ru.

Underlayers for heat assisted magnetic recording (HAMR) media

A perpendicular magnetic recording medium comprises a magnetic recording layer that records a signal, an underlayer formed of Ru or Ru compound below the magnetic recording layer, a non-magnetic layer formed of a non-magnetic material below the underlayer to control crystal orientation of the underlayer, a soft magnetic layer provided below the non-magnetic layer, and a substrate on which the magnetic recording layer, the underlayer, the non-magnetic layer, and the soft magnetic layer are formed. The non-magnetic layer comprises a first non-magnetic layer formed above the soft magnetic layer and a second non-magnetic layer formed above the first non-magnetic layer. The first non-magnetic layer is formed of amorphous Ni compound while the second non-magnetic layer is formed of crystalline Ni or crystalline Ni compound.

Perpendicular magnetic recording medium and method of manufacturing the same

An object of the present invention is to provide a perpendicular magnetic recording medium in which each space between crystal grains of a first magnetic recording layer is so designed as to allow the layer to also have a function as a continuous layer, and a method of manufacturing a perpendicular magnetic recording medium. In a perpendicular magnetic recording medium 100 according to the present invention, a first magnetic recording layer 122 a and a second magnetic recording layer 122 b are ferromagnetic layers each having a granular structure in which a grain boundary part made of a non-magnetic substance is formed between crystal grains each grown in a column shape and, in the first magnetic recording layer 122 a , an intergranular distance defined by an average of shortest distances between grain boundary parts each between a crystal grain and its adjacent crystal grain is equal to or shorter than 1 nm.

Perpendicular magnetic recording medium and process for manufacture thereof

A magnetic recording medium comprises a substrate; a heatsink layer comprising a layer of crystallized CuTi; and a hard magnetic recording layer. The crystallized CuTi is applied in an amorphous state and then crystallized through heating. The use of this heatsink improves surface and underlayer roughness compared to previous heatsink designs.

Low roughness heatsink design for heat assisted magnetic recording media

A composite hard magnetic recording layer for a magnetic storage comprises a hard magnetic layer and a capping layer. The composite recording layer has a crystal structure where crystal grains include a portion within the magnetic layer and a portion within the capping layer.

Composite magnetic recording medium

An energy assisted magnetic recording (EAMR) system includes a magnetic recording medium including a plurality of bi-layers and a magnetic recording layer on the plurality of bi-layers, a magnetic transducer configured to write information to the magnetic recording medium, and a light source positioned proximate the magnetic transducer and configured to heat the magnetic recording medium. Each of the plurality of bi-layers includes a heatsink layer and an amorphous under-layer on the heatsink layer.

Recording media with multiple bi-layers of heatsink layer and amorphous layer for energy assisted magnetic recording system and methods for fabricating the same

Systems and methods for forming magnetic media with an underlayer are provided. One such method includes providing a non-magnetic substrate, forming a seed layer above the substrate, the seed layer including MgO, forming an underlayer on the seed layer, the underlayer including a material selected from the group consisting of Pd, Pt, W, Fe, V, Cu, and Ag, and forming a magnetic recording layer on the underlayer, the recording layer including FePt oxide.

Hua Yuan

Papers

Underlayers for heat assisted magnetic recording (HAMR) media

Low roughness heatsink design for heat assisted magnetic recording media

Composite magnetic recording medium

Recording media with multiple bi-layers of heatsink layer and amorphous layer for energy assisted magnetic recording system and methods for fabricating the same

Systems and methods for forming magnetic media with an underlayer