Abstract: A thin film inductive write head has minimal organic insulation material in contact with the encapsulating overcoat. The process for its fabrication includes a reactive ion etching (RIE) process to remove the organic insulative material while still allowing the head top pole piece to be planar. The organic insulation material is removed by RIE down to the head gap layer in the region between the ABS and the coil. The etching is done with the top or second pole piece acting as a mask so that the planarized organic insulation material is still maintained over the portion of the coil that is located between the two pole pieces. Thus the organic insulation material is still present in this region as the planarization layer onto which the ferromagnetic layer for the second pole piece was deposited.

Abstract: In a method of manufacturing a thin-film magnetic device having a magnetic film provided with uniaxial magnetic anisotropy, the magnetic film, which is formed on a Si wafer, is patterned, before it is heat-treated in a magnetic field, in such a manner that the length of the magnetic film in a direction parallel to that of the magnetic field is greater than the length of the magnetic film in a direction perpendicular thereto. The magnetic film is divided into band-like magnetic films, and the band-like magnetic films are heat-treated in the magnetic field and each provided with uniaxial magnetic anisotropy. The band-like magnetic films are patterned and each divided again into magnetic films of a chip size. Thus, a crack or a blister can be prevented from occurring on the magnetic film, and the magnetic characteristics of the magnetic film can be prevented from deteriorating.

Abstract: In a magneto-optical recording medium including a first magnetic layer which is magnetized in a predetermined direction according to a data signal and a second magnetic layer which is magnetically connected to the first magnetic layer by exchange interaction, so that a boundary magnetic wall can exist between the first magnetic layer and the second magnetic layer, the present invention increases stability of the boundary magnetic wall formed between the first magnetic layer and the second magnetic layer and to enhance a reproduction durability as well as durability against repeated recording.The first magnetic layer and the second magnetic layer are formed by sputtering. At least one of the magnetic layers composing the first magnetic layer and positioned adjacent to the second magnetic layer is formed with a sputter gas pressure greater than the sputter gas pressure applied when forming a magnetic layer composing the second magnetic layer and positioned adjacent to the first magnetic layer.

Abstract: A magnetoresistance effect film is disclosed. This magnetoresistance effect film comprises a substrate, at least two ferromagnetic thin films stacked one over the other on the substrate with a non-magnetic thin film interposed therebetween, and an antiferromagnetic thin film arranged adjacent to one of the ferromagnetic thin films. The antiferromagnetic thin film is a superlattice formed of at least two oxide antiferromagnetic materials selected from NiO, Ni.sub.x Co.sub.1-x O (0.1.ltoreq.x.ltoreq.0.9) and C.sub.o O. A biasing magnetic field Hr applied to the one ferromagnetic thin film located adjacent the antiferromagnetic thin film is greater than coercive magnetic force Hc.sub.2 of the other ferromagnetic thin film.

Abstract: This invention relates to a magnetic stripe comprising a medium in which magnetized particles are suspended and in which the encoded information is recorded by actual physical rotation or alignment of the previously magnetized particles within the flux reversals of the stripe which are 180.degree. opposed in their magnetic polarity. The magnetized particles are suspended in a medium which is solid, or physically rigid, at ambient temperatures but which at moderately elevated temperatures, such as 40.degree. C., is thinable to a viscosity permissive of rotation of the particles therein under applications of moderate external magnetic field strengths within acceptable time limits.

Abstract: A magnetic recording medium is made by applying a coating mixture having magnetic particles dispersed in a binder and drying the coating mixture so as to produce a coding layer containing tamper-proof identifier coding information comprising designed patterns, letters, numerals and bar-code type patterns. Another magnetic layer for recording regular magnetic data can be provided above or below the coding layer. The coding information can neither be read or altered by ordinary magnetic reader. The magnetic recording medium is therefore useful for such applications as shopping cards, pre-paid cards, retail store cards; financial cards including credit cards, insurance cards; travelling cards including transit passes, tickets; and identification cards including passports, birth certificates and other personal identification cards.

Abstract: A surface treatment is provided for magnetic media, in particular metal evaporated magnetic tape, that prevents or reduces corrosion in the media. A corrosion inhibitor and a coupling agent are added to a carrier, such as ethanol, and applied directly to the magnetic media. The corrosion inhibitor is advantageously a derivative of sarcosine, preferably N-methyl-N-(1-oxo-9-octadeconyl)glycine, and is added in an amount up to about 0.5 wt. %. The coupling agent is advantageously an organofunctional silane, preferably 3-glycidoxypropyltrimethoxysilane, and is added in an amount up to about 0.3 wt. %. This formula is particularly suitable for preventing corrosion in cobalt evaporated magnetic tape.

Abstract: The present invention provides a method for producing a magneto-optical recording medium capable of optical intensity modulation direct overwriting, which method enables to easily form an initialization layer having an excellent stability against the magnetization inversion during the optical intensity modulation direct overwriting.

Abstract: A method of fabricating a stable, self-biased paired MR (magnetoresistive) sensor comprising the steps of depositing a first MR film with a diffusion barrier layer on either side on a substrate; depositing an oxide passivation/spacer layer on top of the first MR structure; depositing a second MR film with a diffusion barrier layer on either side on the spacer layer; depositing an oxide passivation layer on top of the second MR structure; wherein the MR films are deposited with induced uniaxial anisotropy; and thermal annealing both MR films to stabilize their anisotropy field.

Abstract: A magnetic multilayer film having magnetoresistance (MR) is prepared by depositing at least two magnetic thin films having different coercive forces while interposing a non-magnetic thin film therebetween. A first magnetic thin film having a lower coercive force has a squareness ratio SQ.sub.1 of 0.01-0.5, an anisotropic magnetic field Hk of 1-20 Oe, and a thickness t.sub.1, a second magnetic thin film having a higher coercive force has a squareness ratio SQ.sub.2 of 0.7-1.0 and a thickness t.sub.2 .ltoreq.t.sub.1, and the non-magnetic thin film has a thickness t.sub.3 .ltoreq.200 .ANG.. A first preferred form requires 4 .ANG..ltoreq.t.sub.2 <30 .ANG. and 6 .ANG..ltoreq.t.sub.1 .ltoreq.200 .ANG.. A second preferred for requires 4 .ANG..ltoreq.t.sub.2 <20 .ANG. and 10 .ANG..ltoreq.t.sub.1 <20 .ANG.. A third preferred form requires 4 .ANG..ltoreq.t.sub.2 <30 .ANG. and 6 .ANG..ltoreq.t.sub.1 .ltoreq.40 .ANG..

Abstract: An MR sensor includes an MR layer and permanent magnets defining an active area on the MR layer. A bi-layer test structure is fabricated with a permanent magnet layer deposited on a substrate and an MR layer deposited on the permanent magnet layer. If desired, a SAL may be deposited prior to deposition of the permanent magnet layer. A DC magnetic field is applied to the bi-layer test structure, and the strength of the DC magnetic field is varied. During application of the DC magnetic field, the magnetic response of the bi-layer test structure is measured to determine a hysteresis loop of the bi-layer structure. The exchange coupling between the permanent magnet layer and the MR layer is characterized by a point of inflection identified on the measured hysteresis loop.

Abstract: Acicular barium ferrite (BaFe) particles with magnetic easy axes perpendicular to particle length are utilized as the magnetic particles in the recording medium of the invention. The BaFe particles are coated to lie "side by side", onto the medium's substrate with the particles' lengths lying in the plane he medium and transverse to the direction of medium motion during recording. The optimum particle orientation for support of both perpendicular and longitudinal components is where the easy axes of the particles are randomly oriented in an X-Y plane wherein the X axis Ks along the direction of media motion, and the Y axis is perpendicular to the recording layer. To effect this random orientation, the just coated particles are subjected to a rotating magnetic field whose rotating vector lies in the X-Y plane.

Abstract: In an extrusion coater having at least two coating slots (8, 8'), the central line between the coating slots is arranged perpendicular to the plane of the substrate (1) and the terminating edge (15) of the separator (16) between the two coating slots is a downward-sloping surface. Opposite the extruder orifice and behind the substrate is the edge (5) of a magnet (2) which draws the magnetizable layers out of the coater outlet orifice (3), the edge (5) being arranged at the height of the common outlet orifice of the coating slots (8, 8'). By means of this arrangement, a uniform coating is achieved even in the case of very thin double layers and even at high coating speeds.

Abstract: A fixed permanent pattern is used for identifying a magnetic recording medium and a high security against forgery or modification is obtained by a magnetic recording medium including a non-magnetic support and at least two magnetic layers formed on said support, characterized in that at least one of said at least two magnetic layers contains magnetic particles having a coercive force of 4,000 Oe or less dispersed in a binder and has a non-rewritable fixed signal which has been recorded by magnetic field generated by a signal recorded on one or more other magnetic layers under the influence of an orientation magnetic field.

Abstract: A magnetic material of at least two component parts arranged to have respective structures which mutually are not homogenous, the structure of one part cooperating with the structure of the other to assist the magnetostrictive behaviour of the material. The cooperation can be the structure of one part altering the atomic spacing of the other part. The alteration can be an increase from the usual atomic spacing. There can be contiguous component parts and the cooperation can be a pseudo free surface on at least one part or a reduced restriction of the local moment otherwise achieved by the contiguous component parts. A component can be at least partly an alloy and the alloy can have a ratio other than the usual one for the alloy. One of the components can be non-magnetic.

Abstract: A method for producing a magnetic recording medium which results in the effective oblique orientation of magnetic fine particles without aggregation of the particles. The method results in a magnetic recording medium having an upper magnetic layer containing needle-shaped, granular, or plate-like magnetic particles, and at least one lower nonmagnetic layer formed on a nonmagnetic support so that the magnetic particles have the maximum degree of orientation in an oblique or perpendicular direction with respect to a surface of the support. The oblique or perpendicular orientation is performed in the wet state of a magnetic layer and in the condition in which the amount of the solvent residue in the upper magnetic layer is 40 to 80% after the upper magnetic layer and the lower nonmagnetic layer are applied sequentially or simultaneously to form a multilayer.

Abstract: An improved extrusion coater having at least two coater slots for applying one or more magnetizable layers to a flexible nonmagnetic substrate is described. The upper lip of the outlet orifice is recessed relative to the lower lip and, in addition, the edge of a right parallelepiped magnet which has a gradient of more than 400 A/cm.sup.2 in the direction of the extruder slot, resulting in a stabilized liquid cushion, is arranged opposite the outlet orifice for the dispersions from the extrusion coater, on the other side of the substrate. It is thus possible to apply very thin layers and to make the meniscus insensitive to interfering forces. To reduce the edge bead, a stripping plate (13) which is extended beyond the range of the upper or lower lip of the extrusion coater, in the direction of the coated material web (1), is mounted at both coating edges, a minimum distance of from 0.05 to 0.8 mm between the surface (19) of the stripping plate (13) and the coated material web being established (FIG. 1).

Abstract: The magnetic recording medium consists essentially of a polymeric substrate, a coherent, magnetic thin metal film applied to the surface of the substrate by a PVD method and, if required, a protective layer formed on the thin metal film. In order to achieve a large residual induction component in the plane of the film, in particular high residual induction in the transverse direction, the thin metal film contains a noble gas or noble gas mixture, preferably argon. During the coating of the polymeric substrate with the magnetic metal or with the magnetic alloy, the noble gas is fed directly and preferably tangentially to the substrate surface at a specific noble gas flow of from 1.0.multidot.10.sup.4 to 6.0.multidot.10.sup.4. In the plane of the thin metal film, the ratio of residual induction in the longitudinal direction to that in the transverse direction is from about 0.9 to about 1.8.

Abstract: An identification tag which can be encoded with multiple bits of information and can be remotely interrogated and read includes a plurality of magnetic elements. The information is stored in the magnetic elements which produce a large domain wall displacement (Barkhausen jump) at a particular magnetic field.

Abstract: A magnetic recording medium having a nonmagnetic supporting member and a plurality of magnetic layers formed on at least one major surface of the nonmagnetic supporting member, comprising a first longitudinally oriented magnetic layer having a first longitudinally orientation rate located uppermost and comprising a hexagonal system ferromagnetic powder, and a second longitudinally oriented magnetic layer having a second longitudinally orientation rate located between the nonmagnetic supporting member and the first longitudinally oriented magnetic layer and comprising a needle-like crystal magnetic powder, wherein the first longitudinally orientation rate of the first longitudinally oriented magnetic layer is at least 0.5 and is smaller than the second longitudinally orientation rate of the second longitudinally oriented magnetic layer.

Abstract: A magnetic recording medium is made by applying a coating mixture having magnetic particles dispersed in a binder and drying the coating mixture so as to produce a coding layer containing tamper-proof identifier coding information comprising designed patterns, letters, numerals and bar-code type patterns. Another magnetic layer for recording regular magnetic data can be provided above or below the coding layer. The coding information can neither be read or altered by ordinary magnetic reader. The magnetic recording medium is therefore useful for such applications as shopping cards, pre-paid cards, retail store cards; financial cards including credit cards, insurance cards; travelling cards including transit passes, tickets; and identification cards including passports, birth certificates and other personal identification cards.

Abstract: A magnetic recording medium which is optimum for high-density recording in which not only orientation of magnetic particles to the direction of thickness of a magnetic layer can be performed effectively but the orientation is maintained, and a method for producing such a magnetic recording medium. The method includes the steps of multiply applying a lower layer containing inorganic powder and resin, an intermediate layer containing resin and an upper layer as a magnetic layer containing needle-shaped ferromagnetic powder onto a non-magnetic support in the condition where all the layers are wet, and drying and solidifying the layers while the ferromagnetic powder contained in the upper layer is oriented at a predetermined angle with respect to the direction of thickness of the intermediate layer. In an another embodiment, only two layers are applied to the support including a non-magnetic layer and a magnetic layer.

Abstract: A method for manufacturing a nonlinear, dual-axis thin-film magnetic device which can be used as an electronic article surveillance system marker. The method includes providing a substrate having a surface characterized by first and second generally perpendicular axes. A magnetic field oriented parallel to the first axis is applied on the surface of the substrate. A first stack of relatively thin thin-film magnetic layers separated by nonmagnetic thin-film layers is grown on the substrate. The relatively thin thin-tim layers are grown in the presence of the magnetic field to a thickness sufficiently thick that the layers exhibit magnetic properties that are substantially independent of surface effects, but sufficiently thin that the easy axis of magnetization is oriented parallel to the second axis. A second stack of relatively thick thin-film magnetic layers separated by nonmagnetic thin-film layers is grown on the first stack.

Abstract: A magnetic recording medium according to the invention comprises a first linear orientation magnetic layer (11) formed of capillary crystal ferromagnetic membrane and a second linear orientation magnetic layer (12) formed of hexagonal system ferromagnetic powder on the first linear orientation magnetic layer, the linear orientation rate of the second linear orientation magnetic layer (12) is smaller than that of the first linear orientation magnetic layer (11).

Abstract: A ferromagnetic .delta.-Mn.sub.1-x Ga.sub.x thin film having perpendicular anisotropy is described which comprises: (a) a GaAs substrate, (b) a layer of undoped GaAs overlying said substrate and bonded thereto having a thickness ranging from about 50 to about 100 nanometers, (c) a layer of .delta.-Mn.sub.1-x Ga.sub.x overlying said layer of undoped GaAs and bonded thereto having a thickness ranging from about 20 to about 30 nanometers, and (d) a layer of GaAs overlying said layer of .delta.-Mn.sub.1-x Ga.sub.x and bonded thereto having a thickness ranging from about 2 to about 5 nanometers, wherein x is 0.4 .+-.0.05.

Abstract: A magnetic recording medium is disclosed comprising a non-magnetic support having provided thereon a plurality of magnetic layers containing a ferromagnetic powder dispersed in a binder, wherein the lower magnetic layer closest to the support contains as the binder at least one polyurethane resin having a glass transition temperature (Tg) of from -50.degree. C. to -10.degree. C., and the uppermost magnetic layer contains as the binder at least one polyurethane resin having a glass transition temperature of from more than 40.degree. C. to 100 .degree. C.The magnetic recording medium of the present invention exhibits excellent running durability as well as electromagnetic conversion characteristics.

Abstract: The present invention forms non-magnetic particles in a acicular shape as dispersed in a dispersoid liquid, forms a lower non-magnetic layer by coating the above-mentioned dispersoid liquid on a continually transported non-magnetic supporting base, forms an upper magnetic layer by coating the above-mentioned magnetic coating liquid in dual layers either consecutively or at the same time while the lower layer is still in its wet state, and performs an orientation of the magnetic particles by exposing the particles to a magnetic field while the dual layers as thus formed are still in their undried state. The orientation effect is achieved by making the specific gravity of the non-magnetic particles equal to or greater than that of the magnetic particles. The orientation effect is further enhanced by making the particle size of the non-magnetic particles equal to or less than that of the magnetic particles as measured along the long axis of the magnetic particles.

Abstract: A method of fabricating a magnetooptic recording medium (10) having at least a reproducing layer (11) and a recording layer (13), from which information is read out by changing the state of magnetization of the reproducing layer (11) comprises steps of forming the reproducing layer (11) on a substrate (21), putting a high-density magnetic recording medium (30) storing information in a high-density magnetic pattern into close contact with the reproducing layer (11) to copy the high-density magnetic pattern formed on the high-density magnetic recording medium (30) into the reproducing layer (11), and forming the recording layer (13) over the reproducing layer (11) after copying the high-density magnetic pattern into the reproducing layer, to copy the high-density magnetic pattern into the recording layer (13).

Abstract: A coating type, magnetic disk is produced by applying a magnetic paint containing magnetic powders in a dispersed state to a non-magnetic substrate, thereby forming a magnetic recording film thereon, and applying surface waves to the magnetic recording film in an undried state. By applying the surface waves to the magnetic recording film, dispersibility and orientation of the magnetic powders are improved and a longitudinally oriented, coating type magnetic disk with distinguished electromagnetic properties, such as a high S/N ratio, etc. can be obtained.

Abstract: Information is magnetically recorded in and reproduced from a magnetic disk using a flying magnetic head. The disk is a coating type disk comprising a rigid substrate having a magnetic layer coated thereont from a magnetic coating composition of ferromagnetic submicron particles in a binder. High density recording is possible when the substrate has a surface roughness Ra of up to 0.007 .mu.m, the magnetic layer has a thickness of up to 0.5 .mu.m, a surface roughness Ra of up to 0.005 .mu.m, and a porosity of 4 to 45%.