Abstract: Magnetic memories and methods are disclosed. A magnetic memory as described herein includes a plurality of stacked data storage layers to form a three-dimensional magnetic memory. The data storage layers are each formed from a multi-layer structure. At ambient temperatures, the multi-layer structures exhibit an antiparallel coupling state with a near zero net magnetic moment. At higher transition temperatures, the multi-layer structures transition from the antiparallel coupling state to a parallel coupling state with a net magnetic moment. At yet higher temperatures, the multi-layer structure transitions from the antiparallel coupling state to a receiving state where the coercivity of the multi-layer structures drops below a particular level so that magnetic fields from write elements or neighboring data storage layers may imprint data into the data storage layer.

Abstract: A recording medium according to the invention has a magnetic recording layer with an L10 magnetic material deposited with a (111) preferred orientation and soft underlayer (SUL). One set of embodiments includes an intermediate layer (seed layer or underlayer) between the L10 media and SUL. The intermediate layer can be a close-packed surface structure (triangular lattice) to promote (111) orientation of the L10 media. For example, the intermediate layer can be a (111) oriented, face-centered-cubic (fcc) material such as platinum, palladium, iridium, rhodium, FePt, FePd, or FePdPt alloys; or the intermediate layer can be a (100) oriented hexagonal-close-packed (hcp) material such as ruthenium, rhenium, or osmium. Alternatively, the intermediate layer can be an amorphous material. The L10 recording layer of the invention can be deposited with a matrix material to form grain boundaries and provide magnetic isolation of the grains of L10 material.

Abstract: A magnetic memory cell for use in a magnetic random access memory array that uses the antiferromagnetic to ferromagnetic transition properties of FeRh to assist in the control of switching of the memory cell.

Abstract: A magnetic recording disk drive has a bilayer recording medium of a high-anisotropy recording layer and an exchange-coupled antiferromagnetic-to-ferromagnetic (AF-F) transition layer. The transition layer has an AF-F transition temperature (TAF-F) that decreases relatively rapidly with increasing applied magnetic field. Thus the transition layer has a transition field HAF-F(T), which is the applied magnetic field required to transition the material from antiferromagnetic to ferromagnetic at temperature T without the need to heat the layer. At ambient temperature and in the absence of HW, the transition layer is antiferromagnetic and the switching field H0 of the bilayer is just the H0 of the high-anisotropy recording layer, which is typically much higher than HW.

Abstract: A layer system, a method for forming the layer system, and devices utilizing the layer system are provided. In one embodiment, the method includes providing a bilayer system comprised of a first layer including a first ferromagnetic material doped with a dopant material selected from one of a 4d transition metal, 5d transition metal, and 4f rare earth metal. The dopant material may be predetermined to provide a magnetic damping in the bilayer which is greater than the magnetic damping in the first ferromagnetic material. The first layer may be very thin, e.g., less than or equal to two nanometers thick. The method also includes providing a second layer disposed on the first layer. The second layer includes a second ferromagnetic material and the second layer may be greater than or equal to two nanometers thick.

Abstract: Solid-state memories are disclosed that are comprised of cross-point memory arrays. The cross-point memory arrays include a first plurality of electrically conductive lines and a second plurality of electrically conductive lines that cross over the first plurality of electrically conductive lines. The memory arrays also include a plurality of memory cells located between the first and second conductive lines. The memory cells are formed from a metallic material, such as FeRh, having the characteristic of a first order phase transition due to a change in temperature. The first order phase transition causes a corresponding change in resistivity of the metallic material.

Abstract: A heating device for a magnetic recording head includes first and second separating layers, the first separating layer having preferably a higher or equal thermal resistance than the first separating layer, and a heater formed between the first and second separating layers. A magnetic recording head for recording on magnetic medium includes a heating device which generates a heat spot on the magnetic medium which is larger than a magnetic track width, and/or heats a portion of the magnetic recording head which is on a leading edge side of a write gap in the magnetic recording head.

Abstract: A thermally-assisted perpendicular magnetic recording head includes a write pole tip for generating a magnetic write field in the perpendicular magnetic recording layer, a magnetic shield that confines the write field essentially to the data track to be recorded, an electrically resistive heater for heating the recording layer in the presence of the write field, and a return pole. The write pole tip width essentially defines data track width and is substantially surrounded by the magnetic shield. The shield may include side shields with ends located on opposite sides of the write pole tip and a trailing shield having an end spaced from the write pole tip. The resistive heater is wider than the data track and heats both the data track and adjacent tracks, but thermally-assisted magnetic recording occurs only in the data track because the confined magnetic field in the adjacent tracks is less than the required write field.

Abstract: The fabrication of the overcoat layer starts with a low energy ion beam to avoid magnetic layer implantation problems, followed by higher deposition energies where the higher energy atoms are implanted into the previously formed lower energy overcoat layer, rather than the magnetic layer. The energy gradient ion beam deposition process therefore results in a thin overcoat layer that is denser than a comparable layer formed by low energy magnetron sputtering, and which overcoat layer provides good mechanical and corrosion protection to the magnetic layer, without degrading the magnetic properties of the magnetic layer.

Abstract: A magnetic recording disk drive has an inductive write head and a heater to record data in laminated media on the recording disk. The laminated media, with at least two ferromagnetic layers separated by a nonmagnetic spacer layer, improves SNR. Each of the ferromagnetic layers can be formed of a material having an intrinsic coercivity capable of being written by a conventional inductive write head, but because of the desired lamination to increase SNR, the ferromagnetic layer farthest from the write head is exposed to a magnetic field less than its intrinsic coercivity and thus can not be written. To write to the laminated media, heat is directed to the lower ferromagnetic layer to reduce its intrinsic coercivity below the magnetic field to which it is exposed.

Abstract: A recording medium according to the invention has a magnetic recording layer with an L10 magnetic material deposited with a (111) preferred orientation and soft underlayer (SUL). One set of embodiments includes an intermediate layer (seed layer or underlayer) between the L10 media and SUL. The intermediate layer can be a close-packed surface structure (triangular lattice) to promote (111) orientation of the L10 media. For example, the intermediate layer can be a (111) oriented, face-centered-cubic (fcc) material such as platinum, palladium, iridium, rhodium, FePt, FePd, or FePdPt alloys; or the intermediate layer can be a (100) oriented hexagonal-close-packed (hcp) material such as ruthenium, rhenium, or osmium. Alternatively, the intermediate layer can be an amorphous material. The L10 recording layer of the invention can be deposited with a matrix material to form grain boundaries and provide magnetic isolation of the grains of L10 material.

Abstract: The invention discloses an assembly comprising an adjustable heat flux mechanism suitable for thermally assisted information processing and control. In one embodiment, the assembly discloses a directed energy source for heating a media, a temperature sensing element for measuring/inferring the temperature of the media, and a controller for mutually positioning the energy output by the directed energy source and the media for thereby controlling the power directed to the media in accordance with the temperature sensing element.

Abstract: A magnetic memory cell for use in a magnetic random access memory array that uses the antiferromagnetic to ferromagnetic transition properties of FeRh to assist in the control of switching of the memory cell.

Abstract: A method for sputtering a thin film protective layer with improved durability is disclosed. The method reduces kinetic energy of the ions of the overcoat material during the initial period of deposition to form a buffering interface which reduces the interpenetration of the atoms of the protective layer into the underlying film. In the method of the invention the sputtering of the overcoat preferably begins with zero (or very low) voltage applied to the underlying film resulting in minimal ion implantation in the underlying film. The “high energy” phase of the process begins with increases in the magnitude of the negative bias voltage applied to the underlying film. The higher energy imparted to ions in the plasma result in a denser and harder film being formed over the initial buffer layer. The protective layer preferably comprises carbon and nitrogen.

Abstract: A magnetic recording disk drive has an inductive write head and a heater to record data in laminated media on the recording disk. The laminated media, with at least two ferromagnetic layers separated by a nonmagnetic spacer layer, improves SNR. Each of the ferromagnetic layers can be formed of a material having an intrinsic coercivity capable of being written by a conventional inductive write head, but because of the desired lamination to increase SNR, the ferromagnetic layer farthest from the write head is exposed to a magnetic field less than its intrinsic coercivity and thus can not be written. To write to the laminated media, heat is directed to the lower ferromagnetic layer to reduce its intrinsic coercivity below the magnetic field to which it is exposed.

Abstract: A magnetic recording system is provided having a write head employing a combination of magnetic write field gradient and thermal gradient to write data on a ‘thermal spring’ magnetic recording media. The write head comprises a magnetic element using a write current to induce a magnetic write field at the magnetic media and a thermal element using a very small aperture laser to heat a portion of the media. The thermal spring magnetic media comprises [comprises] first and second stacks providing two exchange coupled ferromagnetic layers having different Curie temperatures [The first stack has a high magneto-crystalline anisotropy, a relatively low saturation magnetization and a low Curie temperature.] [The second stack has a relatively low magneto-crystalline anisotropy, a high saturation magnetization and a high Curie temperature.

Abstract: A heating device for a magnetic recording head includes first and second separating layers, the first separating layer having preferably a higher or equal thermal resistance than the first separating layer, and a heater formed between the first and second separating layers. A magnetic recording head for recording on magnetic medium includes a heating device which generates a heat spot on the magnetic medium which is larger than a magnetic track width, and/or heats a portion of the magnetic recording head which is on a leading edge side of a write gap in the magnetic recording head.

Abstract: A thermally-assisted perpendicular magnetic recording head includes a write pole tip for generating a magnetic write field in the perpendicular magnetic recording layer, a magnetic shield that confines the write field essentially to the data track to be recorded, an electrically resistive heater for heating the recording layer in the presence of the write field, and a return pole. The write pole tip width essentially defines data track width and is substantially surrounded by the magnetic shield. The shield may include side shields with ends located on opposite sides of the write pole tip and a trailing shield having an end spaced from the write pole tip. The resistive heater is wider than the data track and heats both the data track and adjacent tracks, but thermally-assisted magnetic recording occurs only in the data track because the confined magnetic field in the adjacent tracks is less than the required write field.

Abstract: The fabrication of an overcoat layer starts with a low energy ion beam to avoid magnetic layer implantation problems, followed by higher deposition energies where the higher energy atoms are implanted into the previously formed lower energy overcoat layer, rather than the magnetic layer. The energy gradient ion beam deposition process therefore results in a thin overcoat layer that is denser than a comparable layer formed by low energy magnetron sputtering, and which overcoat layer provides good mechanical and corrosion protection to the magnetic layer.

Abstract: A thermal spring magnetic medium is provided having first and second stacks providing two exchange coupled ferromagnetic layers having different Curie temperatures. The first stack has a high magneto-crystalline anisotropy, a relatively low saturation magnetization and a low Curie temperature. The second stack has a relatively low magneto-crystalline anisotropy, a high saturation magnetization and a high Curie temperature. Preferably the first stack includes an alloy of Fe—Pt or Co—Pt, and the second stack includes an allow of Co—Pt or Co—Pd. A disk drive system having the novel medium is also provided.