Abstract: Methods for fabricating a device component are provided. A substrate comprising a RIE stop layer, an oxide layer formed on the RIE stop layer, and a RIE-able layer formed on the oxide layer may be provided. A resist layer may be patterned on the RIE-able layer. A metal layer may be formed on portions of the RIE-able layer that are not covered by the resist layer. The resist layer may be removed and an RIE performed to remove exposed portions of the RIE-able layer and portions of the oxide layer beneath the exposed portions of the RIE-able layer. Thereafter, the metal layer may be removed, and the component may be formed in an opening in the oxide layer formed during the RIE.

Abstract: A production process of magnetic recording media is provided in which, when using an oxide magnetic material as a perpendicular magnetic recording layer and forming a carbon protective layer using a plasma CVD method, stripping of the carbon protective layer and separation of a lubrication layer can be prevented, and satisfactory recording and reproduction characteristics can be obtained.

Abstract: A magnetic-field sensor device comprises at least two electrodes; an insulating layer separating the at least two electrodes; at least one layer of chemically-synthesized magnetic nanoparticles disposed at or above a level with the insulating layer, and disposed between the at least two electrodes; and an organic spacer surrounding each of the chemically-synthesized magnetic nanoparticles. A deviation between diameters of different ones of the nanoparticles is less than 15%. Moreover, the chemically-synthesized magnetic nanoparticles range in size between 2 nm and 20 nm in diameter.

Abstract: A method of fabricating a bias structure of a magnetoresistive read head for a magnetoresistive sensor stack formed on a substrate includes forming an underlayer and forming a bias layer over the underlayer. The method further includes forming a dusting layer directly below at least one of the underlayer or the bias layer and between the bias layer and the magnetoresistive sensor stack. The dusting layer includes discontinuous, nano-sized islands.

Abstract: Magnetic tunnel junctions are constructed from a MgO or Mg—ZnO tunnel barrier and amorphous magnetic layers in proximity with, and on respective sides of, the tunnel barrier. The amorphous magnetic layer preferably includes Co and at least one additional element selected to make the layer amorphous, such as boron. Magnetic tunnel junctions formed from the amorphous magnetic layers and the tunnel barrier have tunneling magnetoresistance values of up to 200% or more.

Abstract: The invention relates to a perpendicular magnetic recording medium comprising a substrate and a granular magnetic layer comprising ruthenium or ruthenium oxide in the grain boundaries.

Abstract: There are provided a composite magnetic body exhibiting a sufficiently low magnetic loss at frequencies of several hundreds of megahertz to several gigahertz, and a method of manufacturing the same. The composite magnetic body contains a magnetic powder dispersed in an insulating material. The magnetic powder is in a spherical shape or an elliptic shape. The composite magnetic body has any one of the following characteristics (a) to (c): (a) the relative magnetic permeability ?r is larger than 1 and the loss tangent tan ? is 0.1 or less, at a frequency of 1 GHz or 500 MHz; (b) the real part ?r? of the complex permeability is more than 10 and the loss tangent tan ? is 0.3 or less, at a frequency of 1.2 GHz or less; and (c) the real part ?r? of the complex permeability is more than 1 at a frequency of 4 GHz or less, and the loss tangent tan ? is 0.1 or less at a frequency of 1 GHz or less.

Abstract: The present invention provides a method of manufacturing a magnetic recording medium that is made by applying a magnetic paint containing a ferromagnetic powder and a binder to a nonmagnetic support, wherein the magnetic paint contains a magnetic liquid, which contains the ferromagnetic powder and the binder, and a polishing material liquid, which contains a polishing material and a solvent, and wherein the magnetic liquid and the polishing material liquid are individually subjected to dispersion treatment, the magnetic liquid and the polishing material liquid are then mixed together, and after that, a mixed liquid of the magnetic liquid and the polishing material liquid are subjected to dispersion treatment by application of ultrasonic waves.

Abstract: The object of the present is to provide high-quality magnetic recording media capable of easy tracking, and allowing high-density recording, high-speed recording, and higher capacity without increasing the write-current at magnetic heads. The nanohole structure comprises a metal or metal-compound base material and plural arrays of nanoholes, wherein the plural arrays of nanoholes are respectively arranged into regular alignments, the regular alignments are different between adjacent arrays, and the regular alignments are alternately disposed within the metal or metal-compound base material. The magnetic recording medium according to the present invention comprises a substrate, a porous layer into which plural nanoholes are formed, and a magnetic material within the plural nanoholes, wherein the plural nanoholes are formed in a direction approximately vertical to the plane of the substrate, the porous layer is a nanohole structure according to the present invention.

Abstract: A magnetic recording medium includes a support and a magnetic layer containing a ferromagnetic powder and a binder, and has a cut surface along an edge of the magnetic recording medium, wherein the cut surface of the magnetic recording medium has a shear region whose length in a thickness direction of the magnetic recording medium is at least 50% of the thickness of the magnetic recording medium.

Abstract: A method for producing a magnetic recording medium in which the noise of the magnetic recording medium is reduced and the thermal stability of the recorded magnetization is improved, while enabling easy writing to be carried out by a recording head, is disclosed. The magnetic recording medium of the present invention includes an underlayer having an hcp crystal structure and a magnetic layer produced by a multilayer lamination of Co/Pt or the like. The deposition rate of the underlayer is equal to or lower than 0.7 nm/second. The magnetic layer contains added silicon oxide at 1 to 10 mol %. The present method includes a step for subjecting the surface of the underlayer to Ar gas mixed with oxygen of a mass/flow rate ratio of 1% to 10% under a gas pressure of 0.1 to 10 Pa for 1 to 10 second(s). The magnetic recording medium may include an orientation control layer and a soft magnetic backing layer. Ku, Ku1, and Ku2 are controlled to provide both of thermal stability and easy writing.

Abstract: A magnetic thin film structure, a magnetic recording medium including the same, and a method of manufacturing the magnetic recording medium are provided. The magnetic recording medium includes an under layer formed of a transition metal nitride on a substrate and a plurality of magnetic dots, which are unit recording regions, formed of a magnetic material having magnetic anisotropy energy between 106 erg/cc and 108 erg/cc.

Abstract: The invention provides a magnetic recording medium with both weather resistance and high recording density. The magnetic recording medium of the invention has a magnetic layer comprising at least SmCo-based magnetic fine particles and a hydrophobic binder, wherein the SmCo-based magnetic fine particles include a core composed of SmCo-based nanoparticles and a hydrophilic polymer covering at least a portion of the surface of the core.

Abstract: A group of metal magnetic nanoparticles is provided. The metal magnetic nanoparticle includes a core having a noble metal cluster of a diameter of 3 nm or less; and a metal shell, formed to surround the core, having noble metal atoms randomly distributed therein; wherein the metal shell has a noble metal atom content: (number of noble metal atoms)/(number of whole metal atoms)×100 of 1 to 15 at. %.

Abstract: The present invention relates to a method for manufacturing a magnetoresistive element having a magnetization pinned layer, a magnetization free layer, and a spacer layer including an insulating layer provided between the magnetization pinned layer and the magnetization free layer and current paths penetrating into the insulating layer. A process of forming the spacer layer in the method includes depositing a first metal layer forming the metal paths, depositing a second metal layer on the first metal layer, performing a pretreatment of irradiating the second metal layer with an ion beam or a RF plasma of a rare gas, and converting the second metal layer into the insulating layer by means of supplying an oxidation gas or a nitriding gas.

Abstract: A method of forming a micromagnetic device including providing a substrate and forming a magnetic core layer over the substrate from a magnetic alloy. The magnetic alloy includes iron, cobalt and phosphorous. A content of the cobalt is in a range of 1.8 to 4.5 atomic percent. A content of the phosphorus is in a range of 20.1 to 30 atomic percent. A content of the iron is substantially a remaining proportion of the magnetic alloy.

Abstract: A perpendicular magnetic recording medium having a substrate, a soft magnetic buffer layer formed on the substrate, an Ru/Ru alloy underlayer formed on the soft magnetic buffer layer, the Ru/Ru alloy underlayer including Ru or a Ru alloy, a recording layer formed on the Ru/Ru alloy underlayer, the recording layer including at least a layer including a plurality of magnetic particles having an easy axis oriented perpendicular to the substrate, and a non-magnetic material surrounding the plural magnetic particles, and a layered structure interposed between the soft magnetic buffer layer and the Ru/Ru alloy underlayer, the layered structure including at least an Ru/Ru alloy crystalline structure film including Ru or a Ru alloy, a first polycrystalline film including Ru or a Ru alloy, and a second polycrystalline film.

Abstract: An MTJ in an MRAM array or in a TMR read head is comprised of a capping layer with a lower inter-diffusion barrier layer, an intermediate oxygen gettering layer, and an upper metal layer that contacts a top conductor. The composite capping layer is especially useful with a moderate spin polarization free layer such as a NiFe layer with a Fe content of about 17.5 to 20 atomic %. The capping layer preferably has a Ru/Ta/Ru configuration in which the lower Ru layer is about 10 to 30 Angstroms thick and the Ta layer is about 30 Angstroms thick. As a result, a high dR/R of about 40% is achieved with low magnetostriction less than about 1.0 E?6 in an MTJ in an MRAM array. Best results are obtained with an AlOx tunnel barrier layer formed by an in-situ ROX process on an 8 to 10 Angstrom thick Al layer.

Abstract: A magnetic recording medium is provided, comprising a substrate, a hexagonal close-packed seedlayer deposited over the substrate, a hexagonal close-packed underlayer deposited over the seedlayer, and a hexagonal close-packed recording layer deposited over the underlayer. The seedlayer is comprised of a ceramic. A method of manufacturing a magnetic recording medium is also provided, comprising the steps of sputtering a first sputter target to deposit a hexagonal close-packed seedlayer over a substrate, sputtering a second sputter target to deposit a hexagonal close-packed underlayer over the seedlayer, and sputtering a third sputter target to deposit a hexagonal close-packed magnetic recording layer over the underlayer. The seedlayer comprises a ceramic.

Abstract: A ferrite film is formed by regularly arranging constituents such as magnetized grains or one analogous to that. In the ferrite film, the constituents have at least one of the uniaxial anisotropy and the multiaxial anisotropy. The ferrite film has the magnetic anisotropy or the magnetic isotropy. The ferrite film is formed by the use of the plating method in the presence of a magnetic field. Furthermore, an electromagnetic noise suppressor includes the ferrite film.

Abstract: In this invention, we replace low resistivity NiFe with high-resistivity FeNi for the FL2 portion of a composite free layer in a CIP GMR sensor in order to minimize current shunting effects while still retaining both magnetic softness and low magnetostriction. A process for manufacturing the device is also described.

Abstract: A tunneling magnetic detecting element includes an insulating barrier layer having a layered structure including a Ti—O sublayer and a Ta—O sublayer. The Ta concentration in the insulating barrier layer is set to be more than 0 at % but not more than about 7 at % with respect to a total of 100 at % of Ti and Ta constituting the insulating barrier layer.

Abstract: The invention is directed to a magnetic thick film composition comprising particles of permanent magnetic materials dispersed in organic medium wherein the medium comprises a polymer selected from polyurethane, phenoxy and mixtures thereof, and organic solvent.

Abstract: A tunneling magnetic sensing element includes a pinned magnetic layer whose magnetization direction is pinned in one direction, an insulating barrier layer disposed on the pinned magnetic layer, a free magnetic layer whose magnetization direction varies in response to an external magnetic field disposed on the insulating barrier layer, and a first protective layer composed of iridium-manganese (IrMn) disposed on the free magnetic layer. Consequently, a high rate of change in resistance is obtained and the magnetostriction of the free magnetic layer is low, compared with a tunneling magnetic sensing element which is not provided with a first protective layer.

Abstract: On-die inductively coupled wires and a method of making on-die inductively coupled wires are described. The on-die inductively coupled wires include a first wire to carry a first current, a surface area bounded by a second wire, and, an amorphous soft magnetic layer to couple magnetic flux induced by the first current through the surface area.

Abstract: A tunneling magnetic sensing element includes a pinned magnetic layer whose magnetization direction is pinned in one direction, an insulating barrier layer disposed on the pinned magnetic layer, a free magnetic layer whose magnetization direction varies in response to an external magnetic field disposed on the insulating barrier layer, and a first protective layer composed of platinum (Pt) disposed on the free magnetic layer. Consequently, it is possible to greatly decrease the magnetostriction of the free magnetic layer while maintaining a high rate of change in resistance compared with a tunneling magnetic sensing element which is not provided with a first protective layer.

Abstract: By using a free layer that includes a NiFe layer containing between 65 and 72 atomic percent iron, an improved CPP GMR device has been created. The resulting structure yields a higher CPP GMR ratio than prior art devices, while maintaining free layer softness and acceptable magnetostriction. A process for manufacturing the device is also described.

Abstract: Methods and apparatus are provided for magnetic tunnel junctions (MTJs) (10, 50) employing synthetic antiferromagnet (SAF) free layers (14, 14?). The MTJ (10, 50) comprises a pinned ferromagnetic (FM) layer (32, 18), the SAF (14) and a tunneling barrier (16) therebetween. The SAF (14) has a first higher spin polarization FM layer (30) proximate the tunneling barrier (16) and a second FM layer (26) desirably separated from the first FM layer (30) by a coupling layer (28), with magnetostriction adapted to compensate the magnetostriction of the first FM layer (30). Such compensation reduces the net magnetostriction of the SAF (14) to near zero even with high spin polarization proximate the tunneling barrier (16). Higher magnetoresistance ratios (MRs) are obtained without adverse affect on other MTJ (10, 50) properties. NiFe combinations are desirable for the first (30) and second (26) free FM layers, with more Fe in the first (30) free layer and less Fe in the second (26) free layer.

Abstract: A method of manufacturing magnetic recording media, comprising sequential steps of: (a) providing an apparatus for manufacturing the media; (b) supplying the apparatus with at least one substrate for the media; (c) forming a magnetic recording layer on the at least one substrate in a first portion of the apparatus, the magnetic recording layer including a surface; (d) treating the surface of the magnetic recording layer with an ionized oxygen-containing plasma in a second portion of the apparatus to form a plasma oxidized surface layer; and (e) forming a protective overcoat layer on the plasma oxidized surface layer of the magnetic recording layer in a third portion of the apparatus.

Abstract: The present invention relates to a method of producing a magnetic particle including forming a layer containing an alloy particle that can form CuAu type or Cu3Au type hard magnetic order alloy phase on a support, oxidizing the layer, and annealing the layer in non-oxidizing atmosphere. The invention also relates to a method of producing a magnetic particle including producing an alloy particle that can form hard magnetic order alloy phase, oxidizing the alloy particle, and annealing the particle in non-oxidizing atmosphere, and a magnetic particle produced by the foregoing production method. Further, the invention relates to a magnetic recording medium comprising a magnetic layer containing a magnetic particle and a method of producing a magnetic recording medium including forming a layer containing an alloy that can form the foregoing hard magnetic order alloy phase, oxidizing the layer, and annealing the layer in non-oxidizing atmosphere.

Abstract: A perpendicular magnetic recording medium is disclosed that is characterized by a lowered noise component and improved thermal stability. The method for making the recording medium includes the serial steps of forming a soft magnetic back-lining layer on a non-magnetic substrate, forming an intermediate layer on the soft magnetic back-lining layer, forming a magnetic recording layer on the intermediate layer, and forming a protective film and then a liquid lubricating layer on the magnetic recording layer. Thermal treatment is executed after the formation of the magnetic recording layer and before the formation of the protective film, or after the formation of the protective film and before the formation of the liquid lubricating layer. The thermal-processing steps are is executed in a vacuum higher than about 0.1 Pa and in a thermal environment within a range from about 200° C. to about 250° C. for a period of less than about 60 seconds.

Abstract: An improved seed/AFM structure is formed by first depositing a layer of tantalum on the lower shield. A NiCr layer is then deposited on the Ta followed by a layer of IrMn. The latter functions effectively as an AFM for thicknesses in the 40-80 Angstrom range, enabling a reduced shield-to-shield spacing.

Abstract: A perpendicular magnetic recording medium is disclosed. The formation of a domain wall in a soft magnetic backing layer relative to a large external magnetic field can be suppressed better in the medium, the Hk of the backing layer is improved, and productivity can be increased. The perpendicular magnetic recording medium is formed by laminating at least a soft magnetic backing layer, a non-magnetic underlayer, a magnetic recording layer, and a protective film in succession on a non-magnetic substrate. The backing layer, underlayer, magnetic recording layer, and protective film are formed by a vapor deposition method. The backing layer is a laminated body with a soft magnetic lower backing layer, non-magnetic metal layer, and soft magnetic upper backing layer. The non-magnetic metal layer is formed by forming a metal layer and then subjecting the metal layer to surface exposure processing using a nitrogen-containing gas containing 0.1 to 100 at % nitrogen.

Abstract: A method for forming a magnetic head having an improved PtMn layer, including forming a PtMn layer by ion beam deposition, forming an antiparallel (AP) pinned layer structure above the PtMn layer, and forming a free layer above the AP pinned layer structure. The method provides a spin valve structure having improved soft magnetic properties of the free layer as well as increases the dR/R of spin valve structures in which implemented.

Abstract: A process for depositing a diamond-like carbon film, which comprises providing a means for generating a sheet-like beam-type plasma region inside a vacuum vessel for depositing the diamond-like carbon film, and depositing the film on a substrate being moved through said plasma region. Also claimed is an apparatus for fabricating a magnetic recording medium by sequentially and continuously forming a magnetic layer and a diamond-like carbon film on a polymer substrate material, which comprises at least a first vacuum vessel for forming the magnetic layer of the magnetic recording medium and a second vacuum vessel for forming the diamond-like carbon film, provided that the pressure difference between the operation pressures for the first vessel and the second vessel is set in the range of from 10?2 to 10?5 Torr.

Abstract: A magnetic field is applied to planarize magnetic pigment flakes relative to a surface. Pigment flakes, such as optically variable pigment flakes, are used in a variety of paints, inks, extrusions, powder coatings, and other forms for decorative and security applications. In many applications pigment flakes tend to align parallel to each other and to the surface to which they are applied. If the pigment flakes include a suitable magnetic structure, a magnetic field can be applied to subsequently align the flakes or enhance the alignment of the flakes in the plane of the substrate if the carrier that the flakes are dispersed in is still fluid. In some printing operations, pigment flakes that are applied parallel to the substrate are pulled out of plane when the print screen or printing die is lifted off the substrate. Application of a magnetic field can re-align pigment flakes to the plane of the substrate, enhancing the visual quality of the printed image, especially with optically variable pigments.

Abstract: A method of fabricating a magnetic recording medium is disclosed, including a monomolecular film formation step of forming a monomolecular film on a substrate and a magnetic film formation step of forming on the monomolecular film a magnetic film for recording magnetic information. In the monomolecular film formation step, it is preferable to form a perylene-based organic monomolecular film.

Abstract: A method for manufacturing a magnetic recording medium for efficiently and certainly manufacturing a magnetic recording medium. The magnetic recording medium has a recording layer formed to have predetermined concavo-convex pattern and an adequately flat surface. According to this method, a non-magnetic material is deposited on and filled into a member to be processed 10 by adjusting sputtering conditions in such a manner as to satisfy the following Eq I: 0.1?V/V0?0.003×(L·d/t)+1.2 Eq I where V represents a deposition rate which is the film thickness per unit of time, V0 represent a deposition rate in a case that the bias power is zero, t represents the film thickness of the deposited non-magnetic material, L represents the width of a recording element, and d represents the depth of a recessed portion between the recording elements.

Abstract: A method of manufacturing electric machines comprised of geometrically patterned arrays of permanent magnets, soft magnetic materials, and electrical conductors deposited by kinetic spraying methods directly atop a carrier. The magnets and planar coils of the present invention may be integrally formed atop carriers to form electrical machines such as motors, generators, alternators, solenoids, and actuators. The manufacturing techniques used in this invention may produce highly defined articles that do not require additional shaping or attaching steps. Very high-purity permanent and soft magnetic materials, and conductors with low oxidation are produced.

Abstract: A method of manufacturing a magnetoresistance effect element includes forming an insulating layer on a first ferromagnetic layer, forming an aperture reaching the first ferromagnetic layer by thrusting a needle from the top surface of the insulating layer, and depositing a ferromagnetic material to form a second ferromagnetic layer overlying the insulating layer which buries the aperture. The aperture can have an opening width not larger than 20 nm. A current flowing between the first ferromagnetic layer and the needle can be monitored, and thrusting of the needle can be interrupted when the current reaches a predetermined value.

Abstract: A process of preparing gold-coated magnetic nanoparticles is disclosed and includes forming a suspension of magnetic nanoparticles within a suitable liquid, adding an amount of a reducible gold compound and a reducing agent to the suspension, and, maintaining the suspension for time sufficient to form gold-coated magnetic nanoparticles.

Abstract: A perpendicular magnetic recording disk is provided. The perpendicular magnetic recording disk includes an underlayer between a substrate and a perpendicular magnetic recording layer for inducing perpendicular orientation of the perpendicular magnetic recording layer, the perpendicular magnetic recording layer having a thickness in the range where the ratio of perpendicular coercivity Hc to maximum perpendicular coercivity Ho decreases with reduced thickness of the perpendicular magnetic recording layer.

Abstract: A magnetic recording medium has a non-magnetic under-layer, a magnetic layer, a protective film and a liquid lubricant layer sequentially laminated on a non-magnetic substrate. The magnetic layer has a multi-layer structure laminated with two or more magnetic layer components, each of the magnetic layer components having ferromagnetic grains and non-magnetic grain boundaries surrounding the grain. The resulting magnetic recording medium has a granular magnetic layer exhibiting very high Hc accompanying high density of magnetic recording, while decreasing the amount of platinum needed for attaining the high Hc, and reducing media noise accompanying the high recording density.

Abstract: As track widths of magnetic read heads grow very small, conventional longitudinal bias stabilization has been found to no longer be suitable since the strong magnetostatic coupling at the track edges also pins the magnetization of the free layer. This problem has been overcome by extending the free layer so that it is no longer confined to the area immediately below the spacer or tunneling layer. A longitudinal bias layer immediately below the free layer is given a relatively weak magnetic exchange coupling field of about 200 Oe. Although there is strong exchange coupling between this and the free layer, the degree of pinning of the free layer is low so that the device's output signal is reduced by less than about 10%. A process for manufacturing both the CPP SV and a MTJ versions of the invention is described.

Abstract: A magnetic recording medium has a recording layer, disposed above a surface of a substrate and made of hard magnetic nano-particles. The hard magnetic nano-particles are made of an alloy having as a main component an element selected from a group consisting of FePt, FePd and CoPt, and the hard magnetic nano-particles have axes of easy magnetization oriented in a direction approximately perpendicular to the surface of the substrate.

Abstract: A magnetic recording medium having a high coercive force and being capable of high-density writing/reading has a substrate, a soft magnetic layer, a non-magnetic intermediate layer, a magnetic layer, a protective layer, and a lubricating layer. The magnetic layer is characterized by stacking fault density and dispersion of particle diameters. The stacking fault density should preferably be no larger than 0.05, and the dispersion of particle diameters should preferably be no larger than 0.4. The magnetic recording medium has a coercive force larger than 4000 Oe, is highly stable to thermal decay, and has a recording density in excess of 50 Gbit/in2.

Abstract: An electric machine made from kinetically sprayed permanent magnet material and a binder material form a composite admixture having microstructure of permanent magnet material embedded in the binder material. The admixture has a permanent magnetic moment. The magnets of the present invention may be integrally formed atop carriers to form electrical machines such as motors, generators, alternators, solenoids, and actuators. The manufacturing techniques used in this invention may produce highly defined articles that do not require additional shaping or attaching steps. Very high-purity permanent and soft magnetic materials, and conductors with low oxidation are produced.

Abstract: A method of manufacturing a magnetic recording medium facilitates preventing a film inflation from occurring in an environmental condition range between ?40° C. and 80° C. and an 80% relative humidity. The magnetic recording medium includes a plastic substrate and an undercoating layer on the plastic substrate. The undercoating layer is provided with a columnar structure, which prevents water (moisture) between the plastic substrate and the undercoating layer from aggregating and, therefore, the film inflation from occurring.

Abstract: A recording layer of a magneto-optical storage medium having a sublayer in accordance with the present invention comprises a recording layer on which information is recorded and stored; and a sublayer formed above or below the recording layer and made up of an alloy containing a transition metal, wherein a magnetic anisotropy energy of the sublayer is exchange-coupled to the recording layer, thereby enhancing a coercive force of the recording layer. The sublayer may be formed in a single-layered structure having one layer, or in a multi-layered structure having a plurality of layers. The sublayer is preferably made up of an alloy containing a transition metal used for the recording layer. According to the present invention, the coercive force of the recording layer can be increased by an exchange coupling effect between the recording layer and its adjacent sublayer, and thus, the stability of the magnetic domain in the recording layer can be improved.

Abstract: A perpendicular magnetic recording medium has a magnetic recording layer with ferromagnetic crystalline grains and nonmagnetic and nonmetallic grain boundary region surrounding the grains. The surface of its underlayer, before forming the magnetic recording layer, is exposed to an O2 or N2 atmosphere or an atmosphere of rare gas and O2 or N2, to attach the O2 or N2 as nucleation sites for promoting growth of the nonmagnetic and nonmetallic region. By forming the magnetic recording layer thereafter, both ferromagnetic crystalline grains and the nonmagnetic and nonmetallic grain boundary region are formed from the initial stage of the growth of the magnetic recording layer. Thus, a magnetic recording layer having excellent segregation structure can be formed.