A heat-assisted magnetic recording (HAMR) disk has a magnetic recording layer (typically a FePt chemically-ordered alloy), a seed-thermal barrier layer (typically MgO) below the recording layer, a heat-sink layer, and an optical-coupling multilayer of alternating plasmonic and non-plasmonic materials between the heat-sink layer and the seed-thermal barrier layer. Unlike a heat sink layer, the multilayer has very low in-plane and out-of-plane thermal conductivity and thus does not function as a heat sink layer. The multilayer's low thermal conductivity allows the multilayer to also function as a thermal barrier. Due to the plasmonic materials in the multilayer it provides excellent optical coupling with the near-field transducer (NFT) of the HAMR disk drive.

A heat-assisted magnetic recording head includes a near-field emitter and a middle disk. The near-field emitter includes a peg and an anchor disk. The peg is configured to produce a hot spot on a proximal magnetic disk. The peg is disposed proximal to a media-facing surface of the heat-assisted magnetic recording head. The anchor disk is disposed behind the peg relative to the media-facing surface. The middle disk has a melting temperature of at least 1500 degrees Celsius. The middle disk is disposed in a down-track direction relative to the near-field emitter and is coupled to the anchor disk.

A plurality of configuration sets are used with a detector coupled to a decoder. A processor is coupled to the memory registers and the detector and operable to load a first one of the configuration sets into the detector. The detector to attempts detection of the bits in the digital stream for a first iteration between the detector and the decoder using the first configuration set. After the first iteration, a second one of the configuration sets is loaded into the detector. The second configuration set is different than the first configuration set. The detector to attempts detection of the bits in the digital stream for a second iteration between the detector and the decoder using the second configuration set.

A heat-assisted magnetic recording (HAMR) media stack is provided in which Iridium (Ir)-based materials may be utilized as a secondary underlayer instead of a Magnesium Oxide (MgO) underlayer utilized in conventional media stacks. Such Ir-based materials may include, e.g., pure Ir, Ir-based alloys, Ir-based compounds, as well as a granular Ir layer with segregants. The use of Ir or Ir-based materials as an underlayer provide advantages over the use of MgO as an underlayer. For example, DC sputtering can be utilized to deposit the layers of the media stack, where the deposition rate of Ir is considerably higher than that of MgO resulting in higher manufacturing production yields. Further still, less particles are generated during Ir-based layer deposition processes, and Ir-based underlayer can act as a better heat sink. Further still, the morphology and structure of a recording layer deposited on an Ir-based layer can be better controlled.

A magnetic stack includes a substrate and a soft magnetic underlayer deposited on a top surface of the substrate. A heat sink layer is disposed on top of the soft magnetic underlayer, and an interlayer is deposited on top of the heat sink layer. A non-magnetic seed layer is deposited on top of the interlayer. A magnetic recording structure which includes more than one magnetic recording layer is deposited on the top surface of the non-magnetic seed layer.

A heat-assisted magnetic recording (HAMR) medium has a multilayered or laminated heat-sink structure. The laminated heat-sink structure includes a first heat-sink layer and a RuAl—X thermal barrier layer between the medium substrate and the first heat-sink layer. The laminated heat-sink structure may include a second heat-sink layer may between the substrate and the RuAl—X thermal barrier layer. In the RuAl—X thermal barrier layer, X is selected from C and one or more oxides of Si, Ti, W, Zr and Hf. The HAMR medium with the laminated heat-sink structure reduces the amount of required laser current as compared to a similar HAMR medium with a conventional single heat-sink layer of the same thickness, while also slightly improving magnetic properties and recording performance.

A magnetic recording medium for heat-assisted magnetic recording is provided. A magnetic recording layer includes upper and lower magnetic recording layers. The lower magnetic recording layer has a lower granular structure including lower magnetic crystal grains, and a lower non-magnetic portion, that surrounds the lower magnetic crystal grains, mainly composed of carbon. The upper magnetic recording layer has an upper granular structure including upper magnetic crystal grains, and an upper non-magnetic portion, that surrounds the upper magnetic crystal grains, formed from a material selected from the group consisting of silicon nitride, titanium oxide and titanium nitride.

A multidentate lubricant comprising an anchoring moiety Ra attached to a plurality of sidechain moieties —(Rb—Re) according to the general formula: Ra—(Rb—Re).sub.x; wherein Ra is a multivalent radical of valance x; and each sidechain includes a perfluoroethyl ether moiety. The lubricant can be used in conjunction with a magnetic recording medium and/or a magnetic data storage system.

A heat-assisted magnetic recording (HAMR) medium has a multilayered underlayer between the heat-sink layer and the recording layer. One embodiment of the underlayer is a multilayer of a thermal barrier layer consisting essentially of MgO and TiO, and a seed layer containing MgO and nitrogen (N) directly on the thermal barrier layer, with the recording layer on and in contact with the seed layer. The interface between the thermal barrier layer and the seed layer contains Ti and N, some of which may be present as TiN to act as a diffusion barrier to prevent diffusion of the Ti into the recording layer. The Ti-containing thermal barrier layer has a higher thermal resistivity than the conventional MgO thermal barrier/seed layer and thus allows for reduced laser power to the recording layer while still achieving a high thermal gradient at the recording layer.

A magnetic stack includes a substrate and a soft magnetic underlayer deposited on a top surface of the substrate. A heat sink layer is disposed on top of the soft magnetic underlayer, and an interlayer is deposited on top of the heat sink layer. A non-magnetic seed layer is deposited on top of the interlayer. A magnetic recording structure which includes more than one magnetic recording layer is deposited on the top surface of the non-magnetic seed layer.