Abstract: A magnetic recording medium includes a substrate, a soft magnetic underlayer on the substrate, and a dual seed layer. The dual seed layer includes a first seed layer comprising NiFe at a first concentration, and a second seed layer comprising NiFe at a second concentration different from the first concentration and a segregant. The first seed layer may be on a soft magnetic underlayer and the second seed layer is on the first seed layer. The magnetic recording medium may further include one or more magnetic recording layers on the dual seed layer. The magnetic recording medium with the composition-graded dual seed layer may provide small grain size and good crystallographic texture for layers on the dual seed layer, including the magnetic recording layers.

Abstract: A memory cell, including a stack of: a conductive layer of a conductive material including a first chemical element; an oxide layer sufficiently thin to allow the flowing of a current by tunnel effect; and a conductive ferromagnetic layer having a programmable magnetization and including a second chemical element, wherein the oxide layer includes the first and second chemical elements.

Abstract: The present disclosure is directed to a spin current magnetization rotational element, a spin-orbit-torque magnetoresistance effect element, a magnetic memory, and a high-frequency magnetic element which can efficiently generate a pure spin current and reduce a reversal current density. The spin current magnetization rotational element includes: a spin-orbit torque wiring extending in a first direction; and a first ferromagnetic layer laminated in a second direction which intersects the first direction, wherein the spin-orbit torque wiring includes at least one rare gas element of Ar, Kr, and Xe.

Abstract: The magnetic tape device includes a Tunneling Magnetoresistive (TMR) head as a reproducing head; and a magnetic tape which includes a non-magnetic support, and a magnetic layer including ferromagnetic hexagonal ferrite powder and a binding agent on the non-magnetic support, an XRD intensity ratio (Int(110)/Int(114)) of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00, a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm, and a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is equal to or smaller than 0.050.

Abstract: A magnetic recording medium includes a non-magnetic substrate on which at least a soft magnetic underlayer, an orientation control layer, a perpendicular magnetic layer, and a protective layer are disposed. The perpendicular magnetic layer includes first to fourth magnetic layers. A first exchange coupling control layer is disposed between the first magnetic layer and the second magnetic layer. A second exchange coupling control layer is disposed between the second magnetic layer and the third magnetic layer. Following relations are satisfied where Kui is a magnetic anisotropic constant of an i-th magnetic layer, Msi is a saturation magnetization of the i-th magnetic layer, and ti is a film thickness of the i-th magnetic layer, Ku1>Ku2, Ku2>Ku3, Ms1×t1>Ms2×t2, Ms2×t2>Ms3×t3, Ku3<Ku4, and Ms3×t3<Ms4×t4.

Abstract: A gas detection material having a Hofmann type porous coordination polymer of {Fe(pz)[Ni(CN)4]} (wherein, pz=pyrazine) which contains ferrous ion, tetracyanonickelate ion and pyrazine as the essential ingredients and has a pillared crystal shape. Also a lithium ion secondary battery, wherein, the outer package of the lithium ion secondary battery is covered by the gas detection material mentioned above.

Abstract: A perpendicular type of magnetic recording medium has a multi-layered recording structure made up of a plurality of ferro-magnetic layers and a non-magnetic layer interposed between the plurality of ferro-magnetic layers, and the perpendicular magnetic anisotropy energy of the lower ferro-magnetic layer is greater than the perpendicular magnetic anisotropy energy of the upper ferro-magnetic layer. Accordingly, the lower ferro-magnetic layer may be easily magnetically reversed by a magnetic field applied during a write operation. Thus, the perpendicular type of magnetic recording medium exhibits an enhanced thermal stability and write-ability.

Abstract: A magnetic junction usable in a magnetic device is described. The magnetic junction includes a first reference layer, first and second spacer layers, a free layer and a self-initializing (SI) substructure. The first spacer layer is between the free and first reference layers. The free layer is switchable between stable magnetic states when a write current having at least a critical magnitude is passed through the magnetic junction. The second spacer layer is between the SI substructure and the free layer. The SI substructure is selected from first, second and third substructures. The first and second substructures include an SI reference layer having a magnetic moment switchable between the first and second directions when a current having a magnitude of not more than one-half of the critical magnitude is passed through the magnetic junction. The third substructure includes a temperature dependent reference layer.

Abstract: A method for manufacturing a magnetic recording medium including at least a non-magnetic substrate, a soft magnetic underlayer, an orientation control layer that controls an orientation of an immediate upper layer, and a perpendicular magnetic layer in which a magnetization easy axis is mainly perpendicularly oriented with respect to the non-magnetic substrate so as to be laminated one another on the non-magnetic substrate. The perpendicular magnetic layer includes two or more magnetic layers, and each layer is subjected to a crystal growth such that each crystal grain composing each magnetic layer forms a columnar crystal continuous in a thickness direction together with the crystal grains composing the orientation control layer. The orientation control layer, formed of a Co—Cr alloy, is formed by the reactive sputtering using a mixture of a sputtering gas and nitrogen.

Abstract: A magnetic stack includes multiple granular layers, at least one of the multiple granular layers is a magnetic layer that includes exchange coupled magnetic grains separated by a segregant having Ms greater than 100 emu/cc. Each of the multiple granular layers have anisotropic thermal conductivity.

Abstract: A magnetic data storage medium includes an ion doped magnetic recording layer having a continuous grading of coercivity or anisotropy. The medium also includes an ion-doped overcoat having an ion density that is at a maximum substantially at the interface with the recording layer and has a continuous grading of ion density between the overcoat and the recording layer. The coercivity is at a minimum substantially at the interface.

Abstract: A magnetic element capable of reading data may generally be configured at least with a magnetic seed lamination disposed between a data reader stack and a magnetic shield. The magnetic seed lamination may be constructed at least with one magnetic layer coupled to the bottom shield and at least one non-magnetic layer decoupling the data reader stack from the at least one magnetic layer.

Abstract: Methods of fabricating perpendicular magnetic recording media are disclosed. The multilayer structures of the perpendicular magnetic recording media are fabricated by varying the sputtering conditions (i.e., pressure, sputtering gas, etc) in a single sputtering module so that multiple sputtering modules are not needed to form the multilayer structures. These fabrication methods allow sputtering tools with a limited number of chambers, which were designed for the manufacture of longitudinal media, to be used to efficiently produce perpendicular media architectures which heretofore required a large number of sputtering modules. It is further shown that media structures involving a geometric weak-link architecture are suited for these fabrication techniques.

Abstract: A perpendicular magnetic recording media comprises a substrate, a first magnetic oxide layer, a first exchange control layer, a second magnetic oxide layer, a second exchange control layer, and a magnetic cap layer positioned above the substrate, in this order. The first magnetic oxide layer may have an anisotropy energy (Ku) between 6×106 and 8×106 erg/cm3, and a magnetization (Ms) between 600 and 800 emu/cm3. The second magnetic oxide layer may have a Ku between 5×106 and 8×106 erg/cm3, and an Ms between 550 and 750 emu/cm3. The first exchange control layer may have an Ms between 0 and 100 emu/cm3. The second exchange control layer may have an Ms between 0 and 40 emu/cm3.

Abstract: Perpendicular magnetic recording media has been enhanced by controlling the initial growth of magnetic oxide layers and increased magnetic isolation between the grains in the initial magnetic layer. An onset magnetic oxide layer is sputter deposited in an argon-oxygen gas mixture between the main CoPtCr-oxide magnetic layers and the underlying Ru layer. The insertion of the onset magnetic oxide layer enhances the coercivity of the oxide magnetic layers and also improves the nucleation field. The media signal-to-noise ratio and bit error rate also are significantly improved due to the improvement of the initial segregation of Co magnetic grains in the magnetic oxide layers.

Abstract: A perpendicular magnetic recording medium of the present invention comprises a non-magnetic substrate, and at least a backing layer, an under layer, an intermediate layer and a perpendicular magnetic recording layer, which are sequentially laminated on the non-magnetic substrate, wherein the backing layer is formed of a soft magnetic film having an amorphous structure, the under layer contains a NiW alloy containing any one or both of Co and Fe, the W content of the NiW alloy is within a range from 3 to 10 atom %, the total of the Co and Fe contents of the NiW alloy is 5 atom % or more and less than 40 atom %, the saturation magnetic flux density Bs of the NiW alloy is 280 emu/cm3 or more, the thickness of the under layer is within a range from 2 to 20 nm, and the intermediate layer contains Ru or a Ru alloy.

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 perpendicular magnetic recording medium includes a nonmagnetic substrate, and a soft magnetic layer, a first orientation control layer, a second orientation control layer, a nonmagnetic intermediate layer, a magnetic recording layer, and a protective layer layered sequentially on the nonmagnetic substrate. The first orientation control layer includes a thin film having a face-centered cubic (fcc) structure. The magnetic recording layer includes a thin film layer having ferromagnetic crystal grains and nonmagnetic grain boundaries surrounding the ferromagnetic crystal grains, the ferromagnetic crystal grains including a CoPt alloy having ferromagnetic properties, and the nonmagnetic grain boundaries including an oxide or a nitride. The nonmagnetic intermediate layer includes a thin film containing Ru.

Abstract: A method for producing printed magnetic functional elements for resistance sensors and printed magnetic functional elements. The invention refers to the field of electronics and relates to a method for producing resistance sensors, such as can be used, for example, in magnetic data storage for read sensors or in the automobile industry. The disclosure includes a simple and cost-effective production method and to obtain such printed magnetic functional elements with properties that can be adjusted as desire, in which a magnetic material is deposited onto a substrate as a film, is removed from the substrate and divided into several components and these components are applied on a substrate by means of printing technologies. Aspects are also directed to a printed magnetic functional element for resistance sensors of several components of a film, wherein at least 5% of the components of the functional element have a magnetoimpedance effect.

Abstract: A magnetic recording medium includes a substrate, a magnetic layer including an alloy having an L10 type crystal structure, and a plurality of underlayers arranged between the substrate and the magnetic layer. At least one of the plurality of underlayers is a soft magnetic underlayer formed by an alloy having a hexagonal close packed (hcp) structure and including Co metal or Co as its main component, with a (11•0) plane oriented parallel to a surface of the substrate.

Abstract: A magnetic recording medium is disclosed. The magnetic recording medium includes at least a disc-shaped non-magnetic substrate having a hole at a center, a soft magnetic underlying layer, and a magnetic recording layer. Relative permeability of the soft magnetic underlying layer under a magnetic field having one of the frequencies 100 MHz to 700 MHz increases gradually from a disc outer circumference to a disc inner circumference and a characteristic frequency of the relative permeability increases gradually from the disc inner circumference to the disc outer circumference.

Abstract: A magnetic recording medium includes a substrate, a magnetic layer including an alloy having an L10 type crystal structure, and a plurality of underlayers arranged between the substrate and the magnetic layer. At least one of the plurality of underlayers is a soft magnetic underlayer formed by an alloy having a hexagonal close packed (hcp) structure and including Co metal or Co as its main component, with a (11•0) plane oriented parallel to a surface of the substrate.

Abstract: A magnetic recording medium having a thick magnetic recording layer of excellent magnetic characteristics is provided. The magnetic recording medium includes a non-magnetic substrate and a magnetic recording layer. The magnetic recording layer includes a plurality of first magnetic recording layers located at odd-numbered positions from the non-magnetic substrate, and one or more second magnetic recording layers located at even-numbered positions from the non-magnetic substrate. The first magnetic recording layers each have a granular structure that has first magnetic crystal grains with an ordered alloy and a first non-magnetic portion surrounding the first magnetic crystal grains and formed of a material having carbon as main component.

Abstract: According to one embodiment, a patterned magnetic storage medium is disclosed herein. The magnetic storage medium includes a pattern formed on a substrate. The pattern includes at least a first and second feature and an edge defined between the first and second features. Additionally, the magnetic storage medium includes a magnetic layer formed on the pattern. The magnetic layer includes grains separated by a non-magnetic segregant boundary. The segregant boundary is positioned above the edge of the pattern.

Abstract: By improving sliding durability while ensuring a high SNR, an improvement in reliability and a further increase in recording density are to be achieved.

Abstract: A magnetic recording medium is disclosed. The magnetic recording medium includes at least a disc-shaped non-magnetic substrate having a hole at a center, a soft magnetic underlying layer, and a magnetic recording layer. Relative permeability of the soft magnetic underlying layer under a magnetic field having one of the frequencies 100 MHz to 700 MHz increases gradually from a disc outer circumference to a disc inner circumference and a characteristic frequency of the relative permeability increases gradually from the disc inner circumference to the disc outer circumference.

Abstract: A synthetic antiferromagnetic device includes a reference layer having a first and second ruthenium layer, a magnesium oxide spacer layer disposed on the reference layer, a cobalt iron boron layer disposed on the magnesium oxide spacer layer and a third ruthenium layer disposed on the cobalt iron boron layer, the third ruthenium layer having a thickness of approximately 0 angstroms to 18 angstroms.

Abstract: [Problem] An object is to make a film thinner while keeping the function as an auxiliary recording layer and increase an SNR. [Solution] A structure of the perpendicular magnetic disk 100 according to the present invention includes, on a base 110, a granular magnetic layer 160 and an auxiliary recording layer 180 disposed above the granular magnetic layer, the granular magnetic layer having a granular structure in which a non-magnetic substance having an oxide as a main component is segregated around magnetic particles having a CoCrPt alloy as a main ingredient growing in a columnar shape to form a grain boundary part, and the auxiliary recording layer having a CoCrPtRu alloy as a main component and further containing, as a accessory component, a metal forming passivity and not being an antiferromagnet.

Abstract: According to one embodiment, there is provided a magnetic recording medium which includes a base, a magnetic recording layer having convex-shaped magnetic layers, which is formed on the base, and a protective film formed on the magnetic recording layer. There are gaps in a region surrounded by the protective film, the surface of the base, and each side wall of each magnetic layer.

Abstract: There is provided a perpendicular recording medium comprising: a substrate with a seed layer formed thereon; a soft underlayer formed on the seed layer; an orientation control layer formed on the soft underlayer; an intermediate layer formed on the orientation control layer; a flash layer formed on the intermediate layer, the flash layer comprising an oxide; and a recording layer formed on the flash layer.

Abstract: A magnetic recording medium may include an orientation control layer, a lower recording layer, an intermediate layer, and an upper recording layer that are stacked. The lower recording layer may have a coercivity higher than that of the upper recording layer, and the intermediate layer may include a layer including a magnetic material and having a saturation magnetization of 50 emu/cc or higher. The upper recording layer may include columnar crystals continuous with crystal particles forming the intermediate layer in a direction in which the layers are stacked.

Abstract: Embodiments of the invention provide a manufacturing method which permits a high quality perpendicular magnetic recording medium to be manufactured with a high yield by preventing abnormal discharge which sputters particles from the target. In one embodiment, while the perpendicular magnetic recording medium is formed, DC pulses are applied to the target. During the reversal period (Reversal Time) between sputtering periods, a voltage of the opposite polarity is applied. During the sputtering period, a negative voltage is applied which biases the target surface to a negative potential, causing Ar+ to collide with and sputter CoCrPt and SiO2 for deposition on the intermediate layer. The top surface of the insulation material (SiO2) on the target is charged by Ar+ to have a voltage larger than the target voltage. However, arcing can be prevented since the charge on the surface of the insulation material is neutralized due to a positive voltage applied to the target during the non-sputtering period.

Abstract: A bit patterned magnetic recording medium, comprises a non-magnetic substrate having a surface; a plurality of spaced apart magnetic elements on the surface, each of the elements constituting a discrete magnetic domain or bit; and a layer of a ferromagnetic material for regulating magnetic exchange coupling between said magnetic elements. The layer has a saturation magnetization Ms ranging from about 1 to about 2,000 emu/cm3, preferably below about 400 emu/cm3, more preferably below about 200 emu/cm3, and may overlie, underlie, or at least partially fill spaces between adjacent magnetic elements.

Abstract: A perpendicular magnetic recording medium having a dual-layer magnetic film is disclosed. The bottom layer is completely exchange decoupled, and the top layer contains a certain amount of exchange coupling optimized for recording performance. Preferably, the bottom magnetic layer contains stable oxide material (for example, TiO2) and other non-magnetic elements (for example, Cr). A method of manufacturing the media is also disclosed.

Abstract: According to one embodiment, a bit patterned medium includes a substrate, and a magnetic recording layer disposed above the substrate and including patterns of protrusions. Each of the protrusions contains a plurality of crystal grains. An average distance between the crystal grains is 0.5 to 3.0 nm in each of the protrusions. The protrusions include first protrusions each having a length of 1 ?m or more in a radial direction of the medium and second protrusions each having a length in the radial direction shorter than the length of the first protrusion in the radial direction. Each of the first protrusions has a nucleation field Hn for magnetization reversal and a coercive force Hc satisfying the inequalities, Hn?1.5 kOe and 0.5 kOe?Hc?Hn?1.5 kOe.

Abstract: A magnetic tunnel junction device includes a reference magnetic layer and a magnetic free layer including first and second magnetic elements that are magnetically exchange coupled. The magnetic exchange coupling between the first and second magnetic elements is configured to achieve a switching current distribution less than about 200% and a long term thermal stability criterion of greater than about 60 kBT.

Abstract: A corrosion-resistant granular magnetic recording medium with improved recording performance comprises a non-magnetic substrate having a surface; and a layer stack on the substrate surface, including, in order from the surface: a granular magnetic recording layer; an intermediate magnetic de-coupling layer; and a corrosion preventing magnetic cap layer. The intermediate magnetic de-coupling layer has an optimal thickness and/or composition for: (1) promoting magnetic exchange de-coupling between the granular magnetic recording layer and the magnetic cap layer; and (2) reducing the dynamic closure field (Hcl) for determining writeability and eraseability of the medium. Grain boundaries of the magnetic cap layer are substantially oxide-free, and have a greater density and lower average porosity and surface roughness than those of the granular magnetic recording layer.

Abstract: According to embodiments of the present invention, a shielded pole writer and a perpendicular magnetic recording medium suitable thereto are combined to provide high medium SNR and excellent OW characteristic simultaneously. A perpendicular magnetic recording medium of a magnetic storage apparatus mounting a shielded pole writer, including a perpendicular magnetic recording medium having a recording layer of a three layered structure is used. A first recording layer has a granular structure consisting of grain boundaries containing an oxide and columnar grains comprising a CoCrPt alloy, in which a second recording layer and a third recording layer formed thereabove comprise Co as a main ingredient, contain Cr and do not contain an oxide, and the Cr concentration in the second recording layer is lower than the Cr concentration in the third recording layer.

Abstract: A magnetic junction is described. The magnetic junction includes a pinned layer, a nonmagnetic spacer layer, and a free layer. The magnetic junction may also include an additional nonmagnetic spacer layer and an additional pinned layer opposing the nonmagnetic spacer layer and the pinned layer. The nonmagnetic spacer layer is between the pinned layer and the free layer. The free layer is configured to be switchable using a write current passed through the magnetic junction. The free layer is also configured to be thermally stable in a quiescent state and have a reduced thermal stability due to heating from the write current being passed through the magnetic junction. In some aspects, the free layer includes at least one of a pinning layer(s) interleaved with ferromagnetic layer(s), two sets of interleaved ferromagnetic layers having different Curie temperatures, and a ferrimagnet having a saturation magnetization that increases with temperature between ferromagnetic layers.

Abstract: A perpendicular magnetic recording medium having a dual-layer magnetic film is disclosed. The bottom layer is completely exchange decoupled, and the top layer contains a certain amount of exchange coupling optimized for recording performance. Preferably, the bottom magnetic layer contains stable oxide material (for example, TiO2) and other non-magnetic elements (for example, Cr). A method of manufacturing the media is also disclosed.

Abstract: A perpendicular magnetic recording medium according to which both the thermal stability of the magnetization is good and writing with a magnetic head is easy, and moreover the SNR is improved. In the case of a perpendicular magnetic recording medium comprising a nonmagnetic substrate (1), and at least a nonmagnetic underlayer (2), a magnetic recording layer (3), and a protective layer (4) formed in this order on the nonmagnetic substrate (1), the magnetic recording layer (3) comprises a low Ku region (31) layer having a perpendicular magnetic anisotropy constant (Ku value) of not more than 1×105 erg/cm3, and a high Ku region (32) layer having a Ku value of at least 1×106 erg/cm3. Moreover, the magnetic recording layer (3) is made to have therein nonmagnetic grain boundaries that contain a nonmagnetic oxide and magnetically isolate crystal grains, which are made of a ferromagnetic metal, from one another.

Abstract: An apparatus includes a disk substrate and a soft underlayer overlying the disk substrate. A magnetic seed layer overlies the soft underlayer, wherein the magnetic seed layer is formed by a hexagonal close-packed lattice material and has in-plane magnetic anisotropy.

Abstract: Aspects are directed to recording media with enhanced magnetic properties for improved writability. Examples can be included or related to methods, systems and components that allow for improved writability while reducing defects so as to obtain uniform magnetic properties such as uniformly high anisotropy and narrow switching field distribution. Some examples include a recording medium with an exchange tuning layer inserted between the hard layer and the soft, semi-soft or thin semi-hard layer so as to maximize the writability improvement of the media. Preferably, the exchange tuning layer is granular and reduces or optimizes the vertical coupling between the hard layer and the soft, semi-soft or semi-hard layer of a magnetic recording or storing device.

Abstract: The present invention relates to a method of synthesizing an ordered magnetic alloy comprising obtaining a substrate and performing sequential sputter deposition of multiple atomic monolayers of the magnetic alloy.

Abstract: A perpendicular magnetic recording medium 100 having a magnetic recording layer 122, wherein a particle diameter of crystal grains in layer 122 improves a SNR while a high coercive force is maintained. There also is at least a ground layer 118, a first magnetic recording layer 122a, and a second magnetic recording layer 122b in this order on a disk base 110. The first layer 122a and the second layer 122b 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 columnar shape, and A<B when an average particle diameter of the crystal grains in the first magnetic recording layer 122a is taken as A nm and an average particle diameter of the crystal grains in the second magnetic recording layer 122b is taken as B nm.

Abstract: A method for patterning a magnetic thin film on a substrate includes: providing a pattern about the magnetic thin film, with selective regions of the pattern permitting penetration of energized ions of one or more elements. Energized ions are generated with sufficient energy to penetrate selective regions and a portion of the magnetic thin film adjacent the selective regions. The substrate is placed to receive the energized ions. The portions of the magnetic thin film are rendered to exhibit a magnetic property different than selective other portions. A method for patterning a magnetic media with a magnetic thin film on both sides of the media is also disclosed.

Abstract: A perpendicular magnetic recording medium adapted for high recording density and high data recording rate comprises a non-magnetic substrate having at least one surface with a layer stack formed thereon, the layer stack including a perpendicular recording layer containing a plurality of columnar-shaped magnetic grains extending perpendicularly to the substrate surface for a length, with a first end distal the surface and a second end proximal the surface, wherein each of the magnetic grains has: (1) a gradient of perpendicular magnetic anisotropy field Hk extending along its length between the first end and second ends; and (2) predetermined local exchange coupling strengths along the length.

Abstract: In one embodiment, a magnetic recording medium includes a patterned magnetic recording layer above a substrate, the patterned magnetic recording layer including recording regions and separating regions for separating the recording regions and a non-magnetic alloy layer positioned in the separating regions, wherein the non-magnetic alloy layer includes Ti. In another embodiment, a method for producing a magnetic recording medium includes forming separating regions in a magnetic recording layer by removing portions of the magnetic layer, wherein the separating regions separate recording regions in the magnetic layer, and depositing a non-magnetic alloy layer in the separating regions. Other media and methods are described according to more embodiments.

Abstract: In order to provide a magnetic recording medium having excellent electromagnetic conversion characteristics, a magnetic recording medium (10) is provided with a substrate (12), and a magnetic recording layer (20) formed on the substrate (12). The magnetic recording layer (20) is provided with a granular layer (32), i.e., a magnetic layer, including magnetic grains and a nonmagnetic material surrounding the magnetic grains in a section parallel to the main surface of the substrate. The ratio of the long diameter to the short diameter of each magnetic grain contained in the granular layer (32) is calculated in the section. In the histogram of such ratio, a half width at half maximum of the histogram is 0.6 or less and the variance of grain diameters of the magnetic grains in the section is 20% or less of the average grain diameter of the magnetic grains.

Abstract: Approaches to reduce switching field distribution in energy assisted magnetic storage devices involve first and second exchange coupled magnetic elements. The first magnetic elements have anisotropy, Hk1, volume, V1 and the second magnetic elements are magnetically exchange coupled to the first magnetic elements and have anisotropy Hk2, and volume V2. The thermal stability of the exchange coupled magnetic elements is greater than about 60 kBT at a storage temperature of about 300 K. The magnetic switching field distribution, SFD, of the exchange coupled magnetic elements is less than about 200% at a predetermined magnetic switching field and a predetermined assisting switching energy.