Abstract: 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.

Abstract: 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.

Abstract: A magnetic disk according to one embodiment includes a recording layer; and a layer of graphene formed above the recording layer. A nucleation layer may be formed between the recording layer and the graphene layer in some approaches. A magnetic device according to another embodiment includes a transducer; a nucleation layer formed above the transducer; and a layer of graphene formed on the nucleation layer. A method according to one embodiment includes forming a nucleation layer above a magnetic layer of a magnetic disk or magnetic device; and forming a layer of graphene on the nucleation layer. A method according to another embodiment includes depositing SiC above a magnetic layer of a magnetic disk or magnetic device, the SiC being equivalent to several monolayers thick; and surface heating the SiC to selectively evaporate some of the Si from the SiC for forming a layer of graphene on a SiC layer. Additional products and methods are also presented.

Abstract: 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.

Abstract: 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.

Abstract: A method for predicting a characteristic of an overcoat for a media for a hard disc drive is disclosed. An overcoat is probed via a microscope using inelastic scattering of a photon by optical phonons from the overcoat to generate data related to in-plane bond-stretching motion of pairs of atoms of the overcoat. The data is fit to a curve at a computer system. A characteristic of the overcoat is predicted based on the curve at the computer system.

Abstract: 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.

Abstract: 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.

Abstract: An electronic device employing a graphene layer as a charge carrier layer. The graphene layer is sandwiched between layers that are constructed of a material having a highly ordered crystalline structure and a high dielectric constant. The highly ordered crystalline structure of the layers surrounding the graphene layer has low density of charged defects that can lead to scattering of charge carriers in the graphene layer. The high dielectric constant of the layers surrounding the graphene layer also prevents charge carrier scattering by minimizing interaction between the charge carriers and the changed defects in the surrounding layers. An interracial layer constructed of a thin, non-polar, dielectric material can also be provided between the graphene layer and each of the highly ordered crystalline high dielectric constant layers to minimize charge carrier scattering in the graphene layer through remote interfacial phonons.

Abstract: A thermally-assisted recording (TAR) disk has an improved insulating layer beneath the chemically-ordered FePt (or CoPt) alloy recording layer. The insulating layer is a solid substitution crystalline alloy MgXO, where the element X is selected from nickel (Ni) and cobalt (Co). The composition of the MgXO crystalline solid substitutional alloy is of the form (Mg(100-y)Xy)O where y is between 10 and 90, and more preferably between 20 and 80. An optional layer of crystalline “pure” MgO may be located between the MgXO layer and the FePt recording layer and in contact with the recording layer, or between an underlayer and the MgXO layer.

Abstract: A magnetic media has a substrate with an underlayer and a seed layer on the underlayer. The seed layer has a non-continuous metallic layer with a cubed crystalline lattice that is 001 textured, and has a lattice mismatch within 15% of a crystalline lattice structure of FePt with a metallic additive. This structure defines nucleation sites with an established epitaxial interface.

Abstract: A magnetic media for magnetic data recording having a plurality of magnetic grains protected by thin layers of graphitic carbon. The layers of graphitic carbon are formed in a manner similar to onion skins on an onion and can be constructed as single monatomic layers of carbon. The thin layers of graphitic carbon can be formed as layers of graphene or as fullerenes that either cover or partially encapsulate the magnetic gains. The layers of graphitic carbon provide excellent protection against corrosion and wear and greatly reduce magnetic spacing for improved magnetic performance.

Abstract: An electronic device employing a graphene layer as a charge carrier layer. The graphene layer is sandwiched between layers that are constructed of a material having a highly ordered crystalline structure and a high dielectric constant. The highly ordered crystalline structure of the layers surrounding the graphene layer has low density of charged defects that can lead to scattering of charge carriers in the graphene layer. The high dielectric constant of the layers surrounding the graphene layer also prevents charge carrier scattering by minimizing interaction between the charge carriers and the changed defects in the surrounding layers. An interracial layer constructed of a thin, non-polar, dielectric material can also be provided between the graphene layer and each of the highly ordered crystalline high dielectric constant layers to minimize charge carrier scattering in the graphene layer through remote interfacial phonons.

Abstract: An electronic device employing a graphene layer as a charge carrier layer. The graphene layer is sandwiched between layers that are constructed of a material having a highly ordered crystalline structure and a high dielectric constant. The highly ordered crystalline structure of the layers surrounding the graphene layer has low density of charged defects that can lead to scattering of charge carriers in the graphene layer. The high dielectric constant of the layers surrounding the graphene layer also prevents charge carrier scattering by minimizing interaction between the charge carriers and the charged defects in the surrounding layers. An interracial layer constructed of a thin, non-polar, dielectric material can also be provided between the graphene layer and each of the highly ordered crystalline high dielectric constant layers to minimize charge carrier scattering in the graphene layer through remote interfacial phonons.

Abstract: A graphene magnetic field sensor has a ferromagnetic biasing layer located beneath and in close proximity to the graphene sense layer. The sensor includes a suitable substrate, the ferromagnetic biasing layer, the graphene sense layer, and an electrically insulating underlayer between the ferromagnetic biasing layer and the graphene sense layer. The underlayer may be a hexagonal boron-nitride (h-BN) layer, and the sensor may include a seed layer to facilitate the growth of the h-BN underlayer. The ferromagnetic biasing layer has perpendicular magnetic anisotropy with its magnetic moment oriented substantially perpendicular to the plane of the layer. The graphene magnetic field sensor based on the extraordinary magnetoresistance (EMR) effect may function as the magnetoresistive read head in a magnetic recording disk drive.

Abstract: A graphene magnetic field sensor has a ferromagnetic biasing layer located beneath and in close proximity to the graphene sense layer. The sensor includes a suitable substrate, the ferromagnetic biasing layer, the graphene sense layer, and an electrically insulating underlayer between the ferromagnetic biasing layer and the graphene sense layer. The underlayer may be a hexagonal boron-nitride (h-BN) layer, and the sensor may include a seed layer to facilitate the growth of the h-BN underlayer. The ferromagnetic biasing layer has perpendicular magnetic anisotropy with its magnetic moment oriented substantially perpendicular to the plane of the layer. The graphene magnetic field sensor based on the extraordinary magnetoresistance (EMR) effect may function as the magnetoresistive read head in a magnetic recording disk drive.

Abstract: A magnetic disk according to one embodiment includes a recording layer; and a layer of graphene formed above the recording layer. A nucleation layer may be formed between the recording layer and the graphene layer in some approaches. A magnetic device according to another embodiment includes a transducer; a nucleation layer formed above the transducer; and a layer of graphene formed on the nucleation layer. A method according to one embodiment includes forming a nucleation layer above a magnetic layer of a magnetic disk or magnetic device; and forming a layer of graphene on the nucleation layer. A method according to another embodiment includes depositing SiC above a magnetic layer of a magnetic disk or magnetic device, the SiC being equivalent to several monolayers thick; and surface heating the SiC to selectively evaporate some of the Si from the SiC for forming a layer of graphene on a SiC layer. Additional products and methods are also presented.

Abstract: An electronic device employing a graphene layer as a charge carrier layer. The graphene layer is sandwiched between layers that are constructed of a material having a highly ordered crystalline structure and a high dielectric constant. The highly ordered crystalline structure of the layers surrounding the graphene layer has low density of charged defects that can lead to scattering of charge carriers in the graphene layer. The high dielectric constant of the layers surrounding the graphene layer also prevents charge carrier scattering by minimizing interaction between the charge carriers and the charged defects in the surrounding layers. An interracial layer constructed of a thin, non-polar, dielectric material can also be provided between the graphene layer and each of the highly ordered crystalline high dielectric constant layers to minimize charge carrier scattering in the graphene layer through remote interfacial phonons.

Abstract: A magnetic field sensor employing a graphene sense layer, wherein the Lorentz force acting on charge carriers traveling through the sense layer causes a change in path of charge carriers traveling through the graphene layer. This change in path can be detected indicating the presence of a magnetic field. The sensor includes one or more gate electrodes that are separated from the graphene layer by a non-magnetic, electrically insulating material. The application of a gate voltage to the gate electrode alters the electrical resistance of the graphene layer and can be used to control the sensitivity and speed of the sensor.