Abstract: A magnetic recording disc is provided according to the present invention for magnetic recording. The magnetic recording disc includes a disc substrate having a locking pattern etched therein. Chemically synthesized iron-platinum particles are provided in the locking pattern and completely fill the locking pattern. The chemically synthesized iron-platinum nanoparticles exhibit short-range order characteristics forming self organized magnetic arrays.

Abstract: A memory array includes a memory layer that has hysteretic domains with domain axes extending between first and second memory layer surfaces. A conductive layer on the first memory layer surface has anisotropically increased electrical conductivity in a thickness direction. A movable conductive probe has a contact area on the conductive layer and moves to access a selected hysteretic domain.

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.

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 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: Multilayer magnetic structures comprising composite layers and spacer layers are disclosed. The composite layers include a discontinuous magnetic phase such as Co, Ni or Fe platelets, and a continuous nonmagnetic phase such as C, AlOx, SiOx, ZrOx, Cu, Ag and Au. The spacer layers may comprise Pt, Pd, Au or the like. The composite layers and spacer layers may be made by sputtering. The multilayer structures are useful as magnetic recording layers of magnetic recording media. In one embodiment, the recording media comprises a perpendicular magnetic recording medium including a substrate, a soft magnetic underlayer, a seed layer and the multilayer structure.

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 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 composite perpendicular magnetic recording disk has two distinct magnetic layers formed on the disk substrate, each with strong perpendicular magnetic anisotropy, that are strongly exchange coupled perpendicularly to each other across their interface. The first layer is a CoCr granular layer formed on a growth-enhancing sublayer, such as titanium, so as to have strong perpendicular magnetic anisotropy. The second layer is a continuous layer, preferably a continuous multilayer of Co/Pt or Co/Pd palladium formed on top of the granular layer. An interface layer, such as a layer of platinum or palladium, depending on whether the top multilayer is Co/Pt or Co/Pd, respectively, may be located between the two layers to enhance the growth of the continuous multilayer.

Abstract: A magnetic recording disc is provided according to the present invention for magnetic recording. The magnetic recording disc includes a disc substrate having a locking pattern etched therein. Chemically synthesized iron-platinum particles are provided in the locking pattern and completely fill the locking pattern. The chemically synthesized iron-platinum nanoparticles exhibit short-range order characteristics forming self organized magnetic arrays.

Abstract: A method for making a patterned magnetic recording disk uses patterned ion implantation of the disk substrate. Energetic ions, such as He, N or Ar ions, are directed to the disk substrate through a mask, preferably a non-contact mask. They are implanted into the substrate, and the process causes localized topographic distortions in the substrate surface. A magnetic layer is then deposited over the substrate in the conventional manner, such as by sputtering. The result is a disk with patterned magnetic regions that are raised above the substrate surface. Because these regions are elevated, they are closer to the recording head in the disk drive and can thus be individually recorded to form discrete magnetic bits. Depending on the type of substrate used, the ion implantation can cause either localized swelling to form pillars or localized compaction to form pits. The patches of magnetic material on the tops of the pillars, or on the substrate surface between the pits, form the discrete magnetic bits.

Abstract: A magnetic recording disk is patterned into discrete magnetic and nonmagnetic regions with the magnetic regions serving as the magnetic recording data bits. The magnetic recording layer comprises two ferromagnetic films separated by a nonferromagnetic spacer film. The spacer film material composition and thickness is selected such that the first and second ferromagnetic films are antiferromagnetically coupled across the spacer film. After this magnetic recording layer has been formed on the disk substrate, ions are irradiated onto it through a patterned mask. The ions disrupt the spacer film and thereby destroy the antiferromagnetic coupling between the two ferromagnetic films. As a result, in the regions of the magnetic recording layer that are ion-irradiated the first and second ferromagnetic films are essentially ferromagnetically coupled so that the magnetic moments from the ferromagnetic films are parallel and produce a magnetic moment that is essentially the sum of the moments from the two films.

Abstract: A patterned magnetic recording disk has a magnetic recording layer patterned into discrete magnetic and nonmagnetic regions having substantially the same chemical composition. The nonmagnetic regions have a chemically-ordered L12 crystalline structure and the magnetic regions have a chemically-disordered crystalline structure. The chemically-ordered intermetallic compound FePt3, which is nonferromagnetic, is rendered ferromagnetic by ion irradiation. This FePt3 material can be patterned by irradiating local regions through a mask to create magnetic regions that serve as the magnetic bits. The ions pass through the openings in the mask and impact the chemically-ordered FePt3 in selected regions corresponding to the pattern of holes in the mask. The ions disrupt the ordering of the Fe and Pt atoms in the unit cell and transform the FePt3 into magnetic regions corresponding to the mask pattern, with the regions of the film not impacted by the ions retaining their chemically-ordered structure.

Abstract: A patterned magnetic recording disk has a magnetic recording layer patterned into discrete magnetic and nonmagnetic regions having substantially the same chemical composition. The magnetic regions have a chemically-ordered L12 crystalline structure and the nonmagnetic regions have a chemically-disordered crystalline structure. The chemically-ordered intermetallic compound CrPt3, which is ferromagnetic, is rendered paramagnetic by ion irradiation. This CrPt3 material is patterned by irradiating local regions through a mask to create nonmagnetic regions. The ions pass through the openings in the mask and impact the chemically-ordered CrPt3 in selected regions corresponding to the pattern of holes in the mask. The ions disrupt the ordering of the Cr and Pt atoms in the unit cell and transform the CrPt3 into paramagnetic regions corresponding to the mask pattern, with the regions of the film not impacted by the ions retaining their chemically-ordered structure.

Abstract: A patterned magnetic recording disk, i.e., a disk with discrete magnetically recordable regions that can function as discrete magnetic bits, is formed by ion irradiating a continuous magnetic film of a chemically-ordered alloy having a tetragonal crystalline structure through a patterned non-contact mask. The ions cause disordering in the film and produce regions in the film that have no magnetocrystalline anisotropy. The regions of the film not impacted by the ions retain their chemical ordering and magnetocrystalline anisotropy and thus serve as the discrete magnetic regions that can be recorded as individual magnetic bits. The chemically-ordered alloy is preferably Co (or Fe) and Pt (or Pd) with the c-axis of the tetragonal crystalline film oriented at an angle less than 45 degrees relative to the plane of the film, so that after patterning the discrete magnetic regions can be recorded by horizontal magnetic recording.

Abstract: A scanning-aperture electron microscope system and method in which a radiation source generates a radiation beam that is incident upon a surface of a sample material causing electrons to be ejected from the surface. When magnetic imaging is being performed, a polarization rotator polarization-modulates the radiation beam. A scanning-aperture probe having an aperture is positioned in proxiity to the surface of the sample material so that photoelectrons ejected from the surface of the sample material pass through the aperture. A detector detects the electrons passing through the aperture. The electron detector outputs a signal in response to the detected electrons that is used for imaging magnetic and/or spectroscopic features of the surface of the sample material. The resolution of the imaged features is about equal to a size of the aperture.

Abstract: A horizontal magnetic recording medium that has as its magnetic film a granular film with grains of a chemically-ordered FePt or FePtX (or CoPt or CoPtX) alloy in the tetragonal L1.sub.0 structure uses an etched seed layer beneath the granular film. The granular magnetic film reveals a very high magnetocrystalline anisotropy within the individual grains. The film is produced by sputtering from a single alloy target or cosputtering from several targets. The granular structure and the chemical ordering are controlled by means of sputter parameters, e.g., temperature and deposition rate, and by the use of the etched seed layer that provides a structure for the subsequently sputter-deposited granular magnetic film. The structure of the seed layer is obtained by sputter etching, plasma etching, ion irradiation, or laser irradiation. The magnetic properties, i.e., H.sub.c and areal moment density M.sub.

Abstract: The heat gun adapter for accelerated kindling and burning out of combustible solids, (K) especially charcoal, is formed by a shielding cover (1) which is open up to the combustible material (K) and stores and conducts heat to the combustible material (K). The shielding cover has a connecting sleeve (2) for a pipe connection piece (3) that attaches to the heat gun (4).

Abstract: A method for producing a horizontal magnetic recording medium that has as its magnetic film a granular film with grains of a chemically-ordered FePt or FePtX (or CoPt or CoPtX) alloy in the tetragonal L1.sub.0 structure uses an etched seed layer beneath the granular film. The granular magnetic film reveals a very high magnetocrystalline anisotropy within the individual grains. The film is produced by sputtering from a single alloy target or cosputtering from several targets. The granular structure and the chemical ordering are controlled by means of sputter parameters, e.g., temperature and deposition rate, and by the use of the etched seed layer that provides a structure for the subsequently sputter-deposited granular magnetic film. The structure of the seed layer is obtained by sputter etching, plasma etching, ion irradiation, or laser irradiation. The magnetic properties, i.e., H.sub.c and areal moment density M.sub.

Abstract: An alternating current (AC) magnetic force microscopy (MFM) system incorporates an improved probe with an integrated coil on the free end of the system's cantilever. The probe has a pair of magnetic poles that form part of a magnetic yoke and a patterned electrically conductive coil wound through the yoke. The probe includes a probe tip that has a magnetic surface layer that is magnetically coupled to one of the poles and extends from it. When alternating current from the AC-MFM system is passed through the probe coil the magnetization direction of the probe tip correspondingly alternates. The interaction of these alternating magnetic fields from the probe tip with the magnetic fields emanating from the sample whose magnetic fields are to be measured causes the cantilever to deflect between two extreme positions.

Abstract: A probe for use in an alternating current magnetic force microscopy (MFM) system is located on the free end of a cantilever in the MFM system. The probe has a pair of magnetic poles that form part of a magnetic yoke and a patterned electrically conductive coil wound through the yoke. The probe includes a probe tip that has a magnetic surface layer that is magnetically coupled to one of the poles and extends from it. When alternating current from the MFM system is passed through the probe coil the magnetization direction of the probe tip correspondingly alternates. The interaction of these alternating magnetic fields from the probe tip with the magnetic fields emanating from the sample whose magnetic fields are to be measured causes the cantilever to deflect between two extreme positions.

Abstract: An exhaust system for use with a high temperature furnace used to perform oxidation and/or annealing operations of the type used in semiconductor fabrication. The exhaust system is designed to permit the furnace to be used with a controlled environment chamber surrounding the entry to the process chamber of the furnace. The exhaust system allows a relatively high velocity flow of exhaust gas from the process chamber through the exhaust system to occur when a positive pressure (e.g., annealing) operations are performed. Such high velocity flow prevents (a) backstreaming and (b) the accumulation of non-uniform concentrations of exhaust gases in the exhaust system, thereby permitting the accurate monitoring of the concentration of a selected gas in the exhaust system. Based on such monitoring, the opening of the door to the process chamber of the furnace may be prevented when the concentration of the selected gas exceeds a predetermined level.