Abstract: A surface finish which provides improved wirebonding performance for integrated circuit packages is disclosed. The surface finish which is formed on a substrate includes a palladium layer and one or more material layers. The one or more material layers are interposed between the substrate and the palladium layer. The palladium layer has a hardness that is less than about 500 (KHN.sub.50) while at least one material layer has a hardness that is less than about 250 (KHN.sub.50).
Type:
Grant
Filed:
June 10, 1998
Date of Patent:
October 31, 2000
Assignee:
Lucent Technologies Inc.
Inventors:
Joseph Anthony Abys, Alan Blair, Chonglun Fan
Abstract: In order to advantageously solve problems such as lowering of the productivity, contamination of alloy coating due to the adoption of different metal, increase of the cost due to the adoption of different coating process, a coating of MCrAlX alloy is directly formed on a substrate surface of a member exposed to a high temperature at a thickness of 10.about.300 .mu.m through atmospheric plasma spraying process in air or flame spraying process (including low-velocity flame spraying process, high-velocity flame spraying process) and thereafter the same MCrAlX alloy is applied thereonto at a thickness of 100.about.800 .mu.m through low pressure plasma spraying process in a non-oxidizing atmosphere.
Abstract: High temperature oxidation resistance of an aluminide diffusion overcoated MCrAlY coating system is substantially improved by CVD over-aluminizing the MCrAlY type overlay coating under CVD conditions that result in reduced concentrations of such tramp impurities as S and P in the aluminized MCrAlY overlay coating region of the coating system. The CVD aluminizing conditions yield an outwardly grown aluminide over-coat on the underlying MCrAlY type coating.
Type:
Grant
Filed:
August 14, 1997
Date of Patent:
October 10, 2000
Assignee:
Howmet Research Corporation
Inventors:
Bruce M. Warnes, William J. Shriver, Ronald J. Honick, Jr., Nick S. DuShane
Abstract: A magnetic tunnel junction (MTJ) device is usable as a magnetic field sensor in magnetic disk drives or as a memory cell in a magnetic random access (MRAM) array. The MTJ device has a "pinned" ferromagnetic layer whose magnetization is oriented in the plane of the layer but is fixed so as not to be able to rotate in the presence of an applied magnetic field in the range of interest, a "free" ferromagnetic layer whose magnetization is able to be rotated in the plane of the layer relative to the fixed magnetization of the pinned ferromagnetic layer, and an insulating tunnel barrier layer located between and in contact with both ferromagnetic layers. The pinned ferromagnetic layer is pinned by interfacial exchange coupling with an adjacent antiferromagnetic layer. A high spin polarization ferromagnetic layer (Ni.sub.40 --Fe.sub.60) is placed near the tunnel barrier layer in both the pinned and free layers to enhance the magnetoresistive effect. The undesirable positive magnetostriction coefficient of the Ni.sub.
Type:
Grant
Filed:
May 13, 1998
Date of Patent:
October 3, 2000
Assignee:
International Business Machines Corporation
Abstract: A substrate wherein a layer comprising a principal component of nickel and a layer comprising a principal component of palladium are deposited on a glass substrate and wherein an electroconductive layer is deposited on the palladium layer.
Abstract: An article of manufacture includes a substrate and an anchoring layer disposed on a surface of the substrate. The substrate is capable of developing a first oxide on the surface which is tightly bonded thereto and includes a first metallic element. Alternatively, the surface is formed of the first oxide. The anchoring layer is formed with a ternary oxide of the first metallic element, a second metallic element and oxygen. A second oxide layer, which contains an oxide of the second metallic element, is disposed on the anchoring layer. The anchoring layer is formed on the substrate in a series of process steps, which include: establishing an atmosphere containing oxygen around the article; evaporating a compound of the first metallic element and a compound of the second metallic element into the atmosphere and forming a ternary gas phase containing the first metallic element, the second metallic element and the oxygen; and precipitating the ternary gas phase on the article.
Abstract: The present invention discloses an exhaust gas catalyst for reducing the pollutant release containing in the exhaust gas. The catalyst includes a primary-core support carrier composed of gamma-phase aluminum oxide. The core-carrier is coated with Y.sub.2 O.sub.3 and ZrO.sub.2 such that the heat resistance is greatly improved. A two-layer active catalytic structure is formed over the core-carrier. An inner catalytic layer is formed with composition active catalytic elements with approximate weight ratios of La:Ce:Mn:Co:Pd:=10-15:10-15:6-10:6-10:0.1-0.3. An outer catalytic layer is then coated over the inner catalytic layer. The outer catalytic layer comprises catalytic active elements. The weight ratio of the active catalytic elements are Y:La:Zr:Cu:Cr:V:Pd:=1-3:2-6:2-6:6-10:10-15:2-6:0.1-0.3.
Abstract: An austenoferritic stainless steel with high tensile elongation includes iron and the following elements in the indicated weight amounts based on total weight:carbon<0.04%0.4%<silicon<1.2%2%<manganese<4%0.1%<nickel<1%18%<chromium<22%0.05%<copper<4%sulfur<0.03%phosphorus<0.1%0.1%<nitrogen<0.3%molybdenum<3%the steel having a two-phase structure of austenite and ferrite and comprising between 30% and 70% of austenite, whereinCreq=Cr %+Mo %+1.5 Si %Nieq=Ni %+0.33 Cu %+0.5 Mn %+30 C %+30 N %and Creq/Nieq is from 2.3 to 2.75, and whereinIM=551-805(C+N)%--8.52 Si %--8.57 Mn %--12.51 Cr %--36 Ni %--34.5 Cu %--14 Mo %,IM being from 40 to 115.
Abstract: The invention provides an improved near net-shape VPS formed multilayered combustion system component having an inner surface consisting of a smooth protective thermal barrier coating, and an outer layer of superalloy capable of withstanding temperatures in excess of 700.degree. C. The invention also includes the method of forming such components by first vacuum plasma spraying a suitable mold with a ceramic top coat, followed by a bond coat and followed by a thick structural layer of superalloy. The mold is then separated from the multilayered structure which results in the desired near net-shape component. Combustor liners and transition ducts of gas turbine engines can be advantageously formed in this manner.
Type:
Grant
Filed:
July 14, 1998
Date of Patent:
July 11, 2000
Assignee:
Progenesis Inc.
Inventors:
Peter G. Tsantrizos, George E. Kim, Alexander P. Cavasin, Serge Grenier
Abstract: An electrical conductor has a copper base substrate coated with a tin base coating layer. To inhibit the formation of a copper/tin intermetallic and the resultant depletion of the free, unreacted, tin utilized as an oxidation and corrosion barrier, a barrier is interposed between the substrate and the coating. In a first embodiment, the barrier is formed from multiple constituent layers, at least one of which is copper. The thickness ("y") of the copper layer is dependent on the anticipated service temperature and satisfies the equation y=(-1.52+0.0871x+0.00859 t).+-.50% where t=anticipated time at the service temperature, x=anticipated service temperature (Celsius), and y=the thickness of the copper layer in microinches. In a second embodiment, the barrier layer is formed from one or more constituent layers, at least one of which is iron or iron base.
Type:
Grant
Filed:
June 16, 1997
Date of Patent:
July 4, 2000
Assignee:
Olin Corporation
Inventors:
Julius C. Fister, Szuchain F. Chen, Christoper P. Laurello, Arvind Parthasarathi, Derek E. Tyler
Abstract: A Co-base alloy including, by weight, 0.03-0.10% C, not more than 1.0% Si, not more than 1.0% Mn, 20-30% Cr, 15-23% Ni, 3-10% W, 5-10% Ta and 0.05-0.7% Zr, is used as a welding material. A gas turbine nozzle has a crack repaired with a multi-layer weld using the Co-base alloy and a gas turbine for power generation employs the nozzle.
Abstract: A seed layer is deposited under an underlayer in magnetic thin film media. The seed layer material has a similar lattice parameter and a similar crystal structure to the underlayer material. The preferred structure involves a nickel-aluminum seed layer, under a chromium underlayer, under a cobalt-based magnetic layer. Use of the nickel-aluminum seed layer produces higher coercivity and lower media noise in the resultant magnetic thin film. The coercivity and media noise values for the resultant magnetic thin film are dependent upon deposition parameters, and recommended deposition parameters are given.
Abstract: An Mg based article excellent in plating adhesion which is produced with an Mg alloy base material regardless of its kind by forming a Zn layer of an average thickness of 0.60 .mu.m or more, or a Zn deposition of 0.43 mg/cm.sup.2 or more formed on the Mg alloy base material and a method of producing the article with good efficiency are provided.
Type:
Grant
Filed:
April 14, 1998
Date of Patent:
May 30, 2000
Assignee:
Kabushiki Kaisha Kobe Seiko Sho
Inventors:
Jun Kato, Wataru Urushihara, Takenori Nakayama
Abstract: A process for removal of undesirable conductive material (e.g., catalyst material and seeped circuit material) on a circuitized substrate and the resultant circuitized substrates disclosed. Such process and resultant circuit effectively address the electrical shorting problems caused by nonremoval of the residual catalyst material and circuit material which has seeped under the residual catalyst material. The process includes the steps of: a) providing a catalyst layer (e.g., palladium and tin) having circuit pattern (e.g., copper) thereon; b) pretreating the catalyst layer and the circuit pattern (e.g., with a cyanide dip) for removal of undesirable portions of each which cause electrical leakage between circuit lines of the circuit pattern; c) oxidizing the catalyst layer and the circuit pattern (e.g.
Type:
Grant
Filed:
March 6, 1998
Date of Patent:
May 16, 2000
Assignee:
International Business Machines Corporation
Inventors:
Edward Lee Arrington, John Christopher Camp, Robert Jeffrey Day, Edmond Otto Fey, Curtis Michael Gunther, Thomas Richard Miller
Abstract: A microelectronic structure, having 1) at least one metallic feature situated on a layer of material selected from the group consisting of nonmetallic and semiconductor materials; 2) a layer of a cobalt-phosphorus alloy (Co(P)) covering at least one of the at least one metallic feature; and 3) a layer of a material selected from the group consisting of nickel and palladium covering the area covered by the Co(P) layer.
Type:
Grant
Filed:
September 25, 1997
Date of Patent:
May 9, 2000
Assignee:
International Business Machines Corporation
Inventors:
Krystyna W. Semkow, Eugene J. O'Sullivan
Abstract: An exchange coupling film comprises a ferromagnetic film and an antiferromagnetic film laminated on the ferromagnetic film, wherein at least a portion of the antiferromagnetic film has a face-centered cubic crystal structure and the antiferromagnetic film comprises an IrMn alloy represented by the general formula of Ir.sub.x Mn.sub.100-x, wherein x stands for a value by atomic % satisfying the expression, 2.ltoreq.x.ltoreq.80.
Abstract: Composite nanoparticles comprising an elemental metal core surrounded by a metal-containing shell material are described wherein the particles have an average diameter of from about 5-500 nm; the core metal is preferably selected from the group consisting of the transition metals and especially Fe, Co and Ni, whereas the shell material is advantageously a metal such as an alkaline earth metal, or a metal salt such as a metal oxide or metal halide. The shell material is preferably more oxophilic than the elemental core material, enabling the core metal to remain purely metallic. These core/shell composite particles can be used to fabricate magnetizable recording media such as tapes and disks.
Type:
Grant
Filed:
August 5, 1997
Date of Patent:
April 4, 2000
Assignee:
Kansas State University Research Foundation
Inventors:
Kenneth J. Klabunde, Dajie Zhang, Christopher Sorensen
Abstract: A materials system in which exchange coupling is achievable has the potential for allowing direct overwriting of data and comprises at least two multilayer films of platinum and cobalt with independently controlled coercivity and Curie temperatures.
Type:
Grant
Filed:
September 30, 1997
Date of Patent:
February 8, 2000
Assignee:
Johnson Matthey Electronics, Inc.
Inventors:
Joseph Miller, Derek P A Pearson, Philip G. Pitcher
Abstract: This invention relates to a multilayered magnetic structure comprising an alternate stack of:layers (6, 16) of a first type based on magnetic materials,layers (12) of a second type, made of Ag or an Ag rich alloy,a thin interface layer (8, 14) of Co or a Co rich alloy being located at the interface between layers of the first type and layers of the second type.The invention also relates to a process for making this type of structure.Applications to sensors based on magnetoresistive effects, such as current sensors or magnetic heads.
Type:
Grant
Filed:
December 5, 1996
Date of Patent:
January 11, 2000
Assignee:
Commissariat A L'Atomique
Inventors:
Bernard Dieny, Stephane Auffret, Christophe Cowache, Franck Berthet
Abstract: A magnetic recording medium including a substrate and a magnetic layer on the substrate which is a Co-based alloy including Pt and/or Ir, including at least one of Ti, Zr, Hr, V, Nb, Ta, Cr, Mo, W, Ge, and Si, and including oxygen. A magnetic memory apparatus including the magnetic recording medium.
Abstract: An improvement in a magnetic recording medium having an underlayer and first and second magnetic recording layers is described. The improvement, effective to reduce media noise, includes deposition of an interlayer between the first and second magnetic recording layers. The interlayer is deposited to a thickness of between 5-50 .ANG. and is composed of an CoCr-based alloy having a defined saturation magnetization.
Type:
Grant
Filed:
July 2, 1997
Date of Patent:
December 28, 1999
Assignee:
HMT Technology Corporation
Inventors:
Brij Bihari Lal, Sudhir S. Malhotra, Michael A. Russak
Abstract: In a composite material manufactured by connecting a sintered body to a surface of a metal substrate, the connection strength under a high temperature is increased, stress relaxation in the composite material is attained, and the strength, wear resistance and corrosion resistance are improved. The sintered body has a multilayer structure having layers with different compositions, i.e. compositions that vary or differ in a direction perpendicular to the connection surface, and the volume relation between the respective layers of the sintered body and the substrate is (substrate volume.times.0.2).gtoreq.(sintered body volume/number of layers), while the thickness of each layer is at least 0.2 mm and not more than 5 mm.
Abstract: The pin for electronic assemblies according to the present invention consists of a core alloy with 0.2 to 1.5 wt. % Ag, the remainder copper, whereby at least the contact surface of the pin is provided with one or several highly conductive and/or easily solderable coatings. With this not only a higher electric conductivity of the contact is obtained but also a comparatively high strength with simple production and good workability, which makes it possible to miniaturize the pins.
Abstract: A ferrous alloy is formed with a Fe--Cr stainless steel having a Vickers hardness of 400 or more as a substrate and a Fe--Al diffusion layer having a thickness of 2 to 50 .mu.m. The diffusion layer contains at least 90 vol % of an intermetallic compound of Al and Fe relative to a total volume of the diffusion layer. The Al content included within a depth of at least 2 .mu.m of the diffusion layer is 35 to 65% by weight based upon total weight of a region of the diffusion layer ranging up to the thickness of at least 2 .mu.m. It is preferred to use as the substrate a precipitation-hardening stainless steel comprising 66 to 81.9 wt % of Fe, 15 to 20 wt % of Cr, 3 to 13 wt % of Ni, and one element selected from 3 to 6 wt % of Cu, 0.5 to 2 wt % of Al, and 0.01 to 0.2 wt % of a total of C and N, or a high carbon stainless steel comprising 73 to 89.9 wt % of Fe, 10 to 19 wt % of Cr, 0.1 to 1.2 wt % of C, and less than 3 wt % of Ni.
Abstract: A thermal barrier coating and a method for forming the coating on an article designed for use in a hostile thermal environment, such as turbine, combustor and augmentor components of a gas turbine engine. The method is particularly directed to increasing the spallation resistance of a thermal barrier coating system that includes a thermal insulating ceramic layer. The coating system of this invention generally includes a nickel aluminide alloy on which an aluminum oxide layer is formed, over which a ceramic layer is deposited so as to overlie and contact the aluminum oxide layer. The coating system does not include a bond coat, such as a diffusion aluminide or MCrAlY coating known in the prior art. The nickel aluminide alloy may be a binary NiAl alloy consisting essentially of nickel and aluminum in stoichiometric amounts, or may contain one or more oxygen-active elements.
Type:
Grant
Filed:
March 31, 1997
Date of Patent:
November 2, 1999
Assignee:
General Electric Company
Inventors:
Banalore A. Nagaraj, Jon C. Schaeffer, Mark A. Rosenzweig
Abstract: A magnetoresistive film having a spin valve multi-layer structure has low electrical resistance and high sensitivity. In the magnetoresistive film, an under-layer, a first ferromagnetic layer, a non-magnetic layer, a second ferromagnetic layer, and an antiferromagnetic layer are laminated on a substrate in this order. The magnetization direction of the second ferromagnetic layer is fixed by the antiferromagnetic layer, and the magnetization direction of the first ferromagnetic layer is not fixed. The average grain size of the first ferromagnetic layer ranges from 8 to 14 nm.
Abstract: A magnetoresistive element includes a first magnetic layer; and laminations of a second magnetic layer, a non-magnetic layer and a third magnetic layer. The laminations are adjacent to the first magnetic layer. The second magnetic layer and the third magnetic layer have different coercive forces, wherein the first magnetic layer is selected from CoCrTa, NdFe, and alloys thereof.
Abstract: A slide surface construction is formed of an aggregate of metal crystals. The area rate A of hexagonal pyramid-shaped metal crystals in a slide surface of the slide surface construction is in a range of A.gtoreq.40%, and the Co (cobalt) content in the aggregate is in a range of Co.gtoreq.13% by weight. The metal crystals are preferably Fe (ferrous) crystals. The slide surface takes on an intricate aspect due to the existing of a large number of hexagonal pyramid-shaped metal crystals and hence, has a good oil retention. In addition, the wearing of the hexagonal pyramid-shaped metal crystals is inhibited due to an increase in hardness resulting from the incorporation of Co and therefore, the oil retention is maintained. Thus, the slide surface construction exhibits an excellent seizure resistance.
Abstract: An improvement in a magnetic recording medium having an underlayer and a magnetic layer is described. The improvement, effective to increase the coercivity of the medium, includes deposition of an interlayer between the underlayer and the magnetic recording layer. The interlayer is deposited to a thickness of between 10-60 .ANG. and is composed of an CoCr-based alloy having a defined saturation magnetization.
Type:
Grant
Filed:
March 28, 1997
Date of Patent:
July 13, 1999
Assignee:
HMT Technology Corporation
Inventors:
Brij Bihari Lal, Sudhir S. Malhotra, Michael A. Russak
Abstract: A new magnetic alloy exhibits high Hc and Ms while exhibiting excellent corrosion resistance, thereby providing ideal physical properties for high density recording applications. Other parameters of the media, such as SNR, PW50, and S are at least maintained, if not also improved. The alloy contains cobalt and up to 10 at. % Ni, up to 20 at. % Pt, up to 10 at. % Ta, up to 10 at. % Ti, and optionally up to 6 at. % B. The ratio of the tantalum to titanium in the alloy is between 3:1 and 1:3. The alloy is deposited by vacuum deposition (typically sputtering) on a similarly deposited non-magnetic alloy under layer. Nitrogen and/or oxygen may be introduced into the alloy during deposition to improve SNR. Other corrosion-resistant thin film alloys may also be obtained by the inclusion of Ta and Ti.
Type:
Grant
Filed:
October 24, 1996
Date of Patent:
June 1, 1999
Inventors:
Rajiv Yadav Ranjan, Tu Chen, Tsutomu Tom Yamashita, John Ko-Jen Chen
Abstract: An environmental resistant spot type coating is provided on a selected, discrete surface area of a high temperature operating article, by applying to the area a layer of at least one of the elements selected from Pt, Rh and Pd, and preferably Pt, to a thickness of about 0.0002" to less than 0.0006" and an average distribution of at least about 0.07 grams per square inch. The layer is heated at about 1800-2050.degree. F. for about 1/2-4 hours to diffuse the element with the surface area. Then the layer is aluminided to provide an average total coating thickness of about 0.001-0.005". The article provided includes an environmental resistant additive coating diffused with the selected discrete area. The coating comprises an outer portion of at least about 17 wt. % of the selected element, and an aluminide of the surface area or substrate. In one form, the outer portion is a two phase outer portion: a first phase of an aluminide of the selected element at a content of at least about 40 wt.
Type:
Grant
Filed:
February 26, 1996
Date of Patent:
April 27, 1999
Assignee:
General Electric Company
Inventors:
Warren D. Grossklaus, Jr., Richard R. Worthing, Jr.
Abstract: The coercivity of a magnetic recording medium is increased without any substantial change in magnetic remanence by depositing a fresh non-magnetic sub-underlayer on an underlayer or composite underlayer comprising a plurality of sub-underlayers, and immediately depositing a magnetic layer on the fresh sub-underlayer. In an embodiment of the present invention, a fresh chromium sub-underlayer having a thickness of about 55 .ANG. to about 135 .ANG. is sputter deposited on a chromium underlayer in the magnetic layer deposition chamber, and a cobalt magnetic layer deposited on and within 1.2 seconds after depositing the fresh sub-underlayer.
Abstract: A multilayer thin-film structure comprises at least one layered structure formed by depositing a nonmagnetic layer, a first ferromagnetic layer of a ferromagnetic metal or alloy having a positive saturation magnetostriction constant, a nonmagnetic layer and a ferromagnetic layer of a ferromagnetic metal or alloy having a negative saturation magnetostriction constant in that order, and a uniaxial stress is induced in the multilayer thin-film structure. The multilayer thin-film structure for magnetoresistive devices, comprises the magnetic layers which could not have been used for forming the prior art structures and having similar compositions which could not have been used for forming the prior art structure, has an MR ratio in the range of 10 to 20%, does not need the use of antiferromagnetic materials unsatisfactory in corrosion resistance and environment resistance, does not require the turning of a magnetic field when forming the thin films and does not require expensive manufacturing systems.
Abstract: The cladding material 10 comprises an Fe-based metal substrate 1 consisting of Fe or an Fe-alloy, a Ni-based metal layer 2 placed on the Fe-based metal substrate 1 and a metal mesh 3 placed on the Ni-based metal layer 2 in opposition to the Fe-based metal substrate 1 with the Ni-based metal layer 2 inbetween. Furthermore, a corrosion resistant metal lining 4 is placed in contact with the metal mesh 3 in opposition to the Ni-based metal layer 2 with the metal mesh 3 inbetween. The Fe-based metal substrate 1, the Ni-based metal layer 2, the metal mesh 3 and the metal lining 4 are bonded together by seam welded portion 8, which is provided in a planer or a linear form by using roller electrodes 6. The metal lining 4 consists of a metal whose main component is the one selected from Ti, Zr, Nb, Ta and Ni, or consisting of a stainless steel.
Abstract: A masking tape for preventing the formation of coatings such as nickel aluminide on localized areas of a surface is formed from a tape comprising a first separating layer containing powdered metal oxide and a polytetrafluoroethylene binder; a second brazing alloy layer comprising a metal selected from the group consisting of brazing alloy, nickel, cobalt, iron, mixtures thereof, and alloys thereof in a fibrillated polytetrafluoroethylene binder; and an optional third layer comprising a powdered metal selected from the group consisting of nickel, cobalt, and iron in a fibrillated polytetrafluoroethylene binder.
Abstract: A method is provided for bonding a ceramic thermal barrier coating to a nickel or cobalt based superalloy substrate for use in high temperature applications such as gas turbine engines. The method comprises roughening the superalloy substrate itself to produce a surface roughness, preferably from 100 to 350 microinches Roughness Average (RA). The roughened surface of the substrate is treated with a diffusion coating, preferably aluminide or platinum-aluminide to provide oxidation and hot corrosion resistance, while substantially preserving the micro-topography of the roughened surface. A ceramic thermal barrier coating is applied directly to the diffusion treated surface, preferably using an air plasma spray. The surface roughness, which is left substantially undisturbed by the diffusion coating treatment, is altered by the air plasma sprayed ceramic to form a series of interlocking microstructures that firmly attach the ceramic thermal barrier coating to the diffusion treated superalloy substrate.
Type:
Grant
Filed:
October 21, 1997
Date of Patent:
February 2, 1999
Inventors:
Richard J. Stueber, Frank Boorboor, Natarajan S. Palanisamy
Abstract: Disclosed is a spin valve film having a first magnetic layer, a non-magnetic layer, a second magnetic layer, and an antiferromagnetic layer as the fundamental structure for the film. In such structure of the spin valve film, a single-layered film or a multi-layered film consisting of CoZrNb, CoZrMo, FeSiAl or FeSi, or a material prepared by adding Cr, Mn, Pt, Ni, Cu, Ag, Al, Ti, Fe, Co or Zn to the above-mentioned substance is used for at least one of the first magnetic layer and second magnetic layer. According to the present invention, a thin spin valve film having a good sensitivity with respect to magnetic field and a significant magnetoresistive effect can be obtained. When using this thin film for a shield reproducing head or a yoke reproducing head, the maximum reproducing output obtainable is approximately four times that of a reproducing head which utilizes the magnetoresistive effect provided by the application of the prior art.
Abstract: A magnetic recording medium is provided with a structured nucleation layer. The structured nucleation layer comprises a fine-grained seed layer and an intermediate layer. The seed layer (e.g., NiAl, Ti, Cr--Cu, etc.) serves as a template for fine grained-growth of the intermediate layer. The intermediate (e.g., Cr, etc.) layer has preferred crystal textures and an appropriate lattice match to a subsequently deposited magnetic recording layer to allow epitaxial growth of the magnetic recording layer. The intermediate layer provides morphology and orientation to the magnetic recording layer. The magnetic recording layer (e.g., Co-alloy) includes a material which segregates to the alloy grain boundaries to isolate the grains thereof. Each grain of the magnetic recording layer is predominantly a single crystal of small size and uniformly spaced from adjacent grains. The easy axis of the magnetic recording material is predominantly in the plane of the disk, with a random in-plane orientation.
Type:
Grant
Filed:
February 18, 1997
Date of Patent:
December 8, 1998
Assignee:
Komag, Inc.
Inventors:
Tu Chen, Michinobu Suekane, Makoto Imakawa, Kazuhiko Mitarai
Abstract: A method for manufacturing a magnetic disk includes the step of providing first and second magnetic layers on a substrate. The first magnetic layer comprises Co. The portion of the first magnetic layer comprising Cr, Ta, Ti, W, Zr or Hf, if any, is less than 7.5 atomic % of the first magnetic layer (and preferably less than 5 atomic %). The second magnetic layer also comprises Co, and more than 7.5 atomic % of the second layer is Cr, Ta, Ti, W, Zr or Hf (and preferably more than 10 atomic %). We have discovered that the first and second magnetic layers can be made very thin without having a great reduction in coercivity.
Abstract: Pt/Co multilayer systems having a thin metal interlayer possess superior room temperature coercivity, a square polar Kerr hysteresis loop, sufficient polar Kerr rotation, and are suitable for magneto-optical recording. These materials systems allow the reading and writing of information from the substrate side of the multilayer film.
Type:
Grant
Filed:
January 14, 1997
Date of Patent:
November 17, 1998
Assignee:
Johnson Matthey Public Limited Company
Inventors:
Joseph Miller, Derek P. A. Pearson, Philip G. Pitcher
Abstract: A new type of multilayer structure is shown which has superior properties for retaining magnetic transitions on a surface as they are written by a recording transducer. The multilayer is composed of crystal grains which are electronically isolated from one another (exchange isolated). The exchange isolation of the grains creates a type of medium which can viably store data at more than 2 billions bits per square inch. A method is described for making such a structure and the storage of magnetic transitions at extremely high density is demonstrated. Recording with previous multilayer candidates is also shown for comparison purposes.
Abstract: A method for manufacturing a magnetic disk includes the step of providing first and second cobalt alloy layers on a substrate. The first cobalt alloy layer is non-ferromagnetic, and the second cobalt alloy layer is ferromagnetic. The non-ferromagnetic layer is deposited on an underlayer. The non-ferromagnetic cobalt alloy provides a better crystal structure for depositing the subsequent ferromagnetic layer and thereby improves its magnetic properties. However, because the first cobalt alloy layer is not ferromagnetic, it does not adversely affect the magnetic characteristics of the disk.
Abstract: Disclosed is a perpendicular magnetic recording/reproducing apparatus comprising perpendicular magnetic recording media and magnetic heads. Each perpendicular magnetic recording medium has a substrate, a soft magnetic back layer and a magnetic recording layer with a perpendicular magnetic anisotropy both formed on the substrate. Each magnetic head has at least one magnetic field generating element capable of applying a magnetic field to a given region of the soft magnetic back layer at a time of signal reproduction, for performing recording and reproducing of magnetized signals with respect to the associated perpendicular magnetic recording media, whereby Barkhausen noise is reduced. The perpendicular magnetic recording medium may further include a bias-field applying layer formed on at least a substrate side surface of the soft magnetic back layer. Each perpendicular magnetic recording medium may further have the bias-field applying layer formed between the substrate and the high-permeability magnetic layer.
Abstract: A magneto-optical recording medium comprises in combination: a magneto-optical recording layer capable of writing or erasing information by a laser beam and an external magnetic field and of reading the information by a Kerr effect; and a substrate having the magneto-optical recording layer formed thereon. The magneto-optical recording layer has at least two layers, including a first magneto-optical recording layer and a second magneto-optical recording layer which are magnetically coupled together. The first magneto-optical recording layer is a layer providing a greater magneto-optical effect in a short light wavelength range than the second magneto-optical recording layer though that having less perpendicular magnetic energy than this, as is provided on an irradiation side of the laser beam. It provides advantages in both the magneto-optical effect and perpendicular anisotropy in consideration of the thicknesses or compositions of the first and second magneto-optical recording layers.
Abstract: The present invention provides a longitudinal magnetic recording media having a substrate, a sputter deposited MgO seed layer, a Co or Co alloy based magnetic layer and an underlayer disposed between the seed layer and the magnetic layer comprised of Cr, a Cr alloy or a material having a B2 ordered crystalline structure, preferably NiAl or FeAl. A thin Cr or Cr alloy intermediate layer of about 1.0 nm to 5.0 nm thick may be positioned between the underlayer and the magnetic layer.
Type:
Grant
Filed:
November 6, 1995
Date of Patent:
September 1, 1998
Assignee:
Carnegie Mellon University
Inventors:
Li-Lien Lee, David N. Lambeth, David E. Laughlin, Byung-Ki Cheong
Abstract: Disclosed is magnetic recording media having a high coercivity sufficient to cope with the recent high density recording, low noise property and excellent squareness, and a target for forming a magnetic film useful for realizing the magnetic recording media. The magnetic film is made of a Co based alloy containing: Cr in an amount of 8-18 atomic %; one kind or more of elements selected from a group consisting of V, Mo and W in an amount of 3-10 atomic %, or one kind or more of the elements and Ta in an amount of 3-10 atomic %; Pt in an amount of 0.5 to 20 atomic % or Ni in an amount of 5-30 atomic %, as needed; and the balance being Co and inevitable impurities, wherein the total content of Cr and one kind or more of the elements selected from a group consisting of V, Mo and W, or of Cr and one kind or more of the elements and Ta is specified to be 24 atomic % or less.
Abstract: The present invention relates to a magnetic recording medium for use in an external memory device of an information processing apparatus etc., and an object thereof is to reduce noise, achieve high coercive force, and use the substance as a magnetic recording medium for detecting signals in a magnetoresistance head. In the magnetic recording medium comprising the magnetic recording layer 25 including ferromagnetic grains 22 and a nonmagnetic substance 23, the improvement in structure comprises that the ferromagnetic grains 22 are formed to have respectively an average grain diameter of 50 nm or less and not to be overlapped in the film thickness direction and to be isolated in the direction along a layer surface, and that a product of residual magnetization and a film thickness of the magnetic recording layer 25 is less than or equal to 150 Gauss.cndot..mu.m.
Abstract: The present invention relates to improved multi-layer magnetic recording media and magnetoresistive drive systems incorporating the same. In particular, multi-layer media including alternating layers of cobalt or cobalt alloys and a precious metal, such as palladium or platinum, and a process to manufacture such media, are disclosed. Media in accordance with the invention generally include a substrate, a nucleating layer, a lattice, and a protective layer. In certain embodiments, the substrate is polished aluminum. In other embodiments, the thickness of the nucleating layer is thicker than 100 .ANG., and in certain embodiments between about 200 and about 600 .ANG.. The lattice, generally includes bilayers of cobalt (or an alloy thereof) and palladium or platinum. The thickness of the cobalt layers are between about 1.5 .ANG. and 10 .ANG., or between about 2 .ANG. and 7 .ANG., or between about 3 .ANG. and 5 .ANG.. The thickness of the palladium or platinum layers are between about 5 .ANG. and 15 .ANG.
Abstract: Active and adaptive vibration damping devices are provided. The damping devices include heterostructures having a layer of ferroelastic or SME material coupled with a first and second layer of ferroelectric material having a layer of dielectric material therebetween. Methods of making the active and adaptive vibration damping devices are also provided.
Type:
Grant
Filed:
February 10, 1995
Date of Patent:
May 12, 1998
Assignee:
The Research Foundation of State University of New York
Abstract: A magnetooptic medium comprising a substrate, an amorphous seed layer and a recording multilayer deposited onto the seed layer wherein the seed layer has a thickness of greater than 18 nm but less than 200 nm and is selected to improve the coercivity, squareness, and Kerr rotation of the Kerr hysteresis loop of the recording multilayer, and the recording multilayer includes alternating layers of cobalt and platinum or cobalt and palladium or cobalt and platinum-palladium alloy.
Type:
Grant
Filed:
June 28, 1996
Date of Patent:
May 12, 1998
Assignee:
Eastman Kodak Company
Inventors:
Tukaram K. Hatwar, Yuan-Sheng Tyan, Charles F. Brucker