Abstract: The present invention provides a thin film magnetic head capable of satisfying both assurance of recording performance and assurance of reproduction performance. In the case where a lower magnetic layer is formed of an iron cobalt alloy (for example, Fe65Co35) which contains iron in a range of 60 at % to 80 at % and has extremely high saturation magnetic flux density of 2.4 T or higher, a head isolation layer formed of ruthenium (Ru) is provided between the lower magnetic layer and an upper read shield layer portion. As compared with the case where the head isolation layer is not provided between the lower magnetic layer and the upper read shield layer portion, the strength of a recording magnetic field increases and a reproduction output of an MR element is stabilized.

Abstract: A perpendicular magnetic recording element includes a recording magnetic pole film and a write shield film. The recording magnetic pole film has a yoke portion and a main magnetic pole for perpendicular recording. The main magnetic pole projects from a front end of the yoke portion to have an end on a medium-facing surface. The write shield film faces the recording magnetic pole film and has a height equal to or smaller than that of the recording magnetic pole film, as measured rearward from the medium-facing surface.

Abstract: A pole layer incorporate a track width defining and a wide portion. A material forming the pole layer is an alloy whose major elements are iron and nickel. In the alloy, where the proportions of iron and nickel with respect to the total of iron and nickel are indicated as (100-M) weight % and M weight %, respectively, M is greater than 0 and smaller than or equal to 10. The internal stress of the pole layer is a tensile stress. The magnetostriction constant of the material forming the pole layer is positive. Where the anisotropy field of the pole layer is Hk (A/m), the magnetostriction constant of the material forming the pole layer is ?(×10?6), and the internal stress of the pole layer is ? (MPa), the value of Hk/(?×?) is greater than 0.01 and smaller than 0.2.

Abstract: Disclosed is a method for determining whether a dog is an extensive metabolizer or a poor metabolizer in the rate of drug metabolism, by preparing a DNA sample from a dog, and determining a base corresponding to a base at position 1117 of a canine CYP1A2 gene (i.e., at position 87 of exon 4). According to the method, a CYP1A2 gene diagnosis of dogs (particularly beagles) used in a pharmacological effect test or a toxicity test can be rapidly carried out prior to the test, and thus the dogs can be easily divided into a group having a normal metabolic ability (an extensive metabolizer group) and a group having a low metabolic ability (a poor metabolizer group).

Abstract: The invention provides a magnetic head for perpendicular magnetic recording having an air bearing surface positioned facing the recording surface of a recording medium, which records magnetic information on the recording medium by generating magnetic flux toward the recording surface of the recording medium, and comprises a magnetic pole which generates magnetic flux toward the recording surface of the recording medium and a return yoke having one end connected to the magnetic pole and the other end positioned facing the recording surface of the recording medium, wherein the material composing the magnetic pole has a magnetostriction constant ? of at least 0 and less than 10×10?6, with a parameter P represented by the formula: P=Hk/(?×?) (where Hk represents the magnetic anisotropic field (A/m), ? represents the stress (MPa) and ? represents the magnetostriction constant) of larger than 0.1 and less than 200.

Abstract: A thin-film magnetic head comprising an inductive element including at least: a lower magnetic pole; a write gap layer; and an upper magnetic pole opposed to the lower magnetic pole through the write gap layer, a width WP2 in a track-width direction at a facing-to-magnetic-medium top end of the upper magnetic pole being larger than a width WP1 in the track-width direction at a facing-to-magnetic-medium top end of the lower magnetic pole, and a distance FPDP2 between the top end of the upper magnetic pole and a flare point of the upper magnetic pole being smaller than a distance FPDP1 between the top end of the lower magnetic pole and a flare point of the lower magnetic pole, is provided.

Abstract: The present invention is intended for a thin film magnetic head which can provide reduction in the excess magnetostatic leakage field even if the flare point is set near to the ABS in order to generate a sufficient recording magnetic field and which can assure stable overwrite characteristics even if there are variations in upper pole portion patterns. The pole end portion 223 has a width W11 to define a recording track width. The pole rear portion 222 has one end which is magnetically connected with the pole end portion 223 at or in the vicinity of an edge portion of an insulating film 273 and defines a first flare point FP1, the other end which is connected with the upper yoke portion 221 and defines a second flare point FP2, and both side edges in the track width direction which are inclined so that the width in the track width direction gradually increases from the second flare point FP2 toward the first flare point FP1.

Abstract: A method for forming a bottom spin valve sensor having a synthetic antiferromagnetic pinned (SyAP) layer, antiferromagnetically coupled to a pinning layer, in which one of the layers of the SyAP is formed as a three layer lamination that contains a specularly reflecting oxide layer of FeTaO. The sensor formed according to this method has an extremely high GMR ratio and exhibits good pinning strength.

Abstract: A thin-film magnetic head includes a lower magnetic layer, an upper magnetic layer, a recording gap layer, and a thin-film coil. The lower magnetic layer has a first magnetic pole tip layer, and a first yoke layer which is connected to the first magnetic pole tip layer. The first yoke layer has an extended part which is relatively thick and a reduced part which is relatively thin in the area in which the first yoke layer confronts the first magnetic pole tip layer, the extended part being positioned on the side of the air bearing surface. Further, the first magnetic pole tip layer is connected to the first yoke layer at the extended part, and is insulated from the first yoke layer at the reduced part.

Abstract: The soft magnetic film takes its hard axis along the direction in which a magnetic field is generated and its easy axis along a direction perpendicular to the direction of the writer magnetic field. The magnetic bias film applies a magnetic bias along the easy axis to the soft magnetic film.

Abstract: A bottom pole layer incorporates a pole portion layer and a yoke portion layer. A top pole layer incorporates a pole portion layer and a yoke portion layer. The pole portion layer of the bottom pole layer, a write gap layer, and the pole portion layer of the top pole layer have cross sections of the same shapes, the cross sections being parallel to the top surface of a substrate. The aggregate of both pole portion layers and the write gap layer includes a first portion having a width that defines the track width and a second portion having a width greater than the width of the first portion. Where the width of the first portion is W and the distance from a medium facing surface ABS to the interface between the first portion and the second portion is L, L/W falls within a range of 2 to 5 inclusive. Where the area of the cross section of the aggregate parallel to the top surface of the substrate is S, S/(W×L) falls within a range of 5 to 40 inclusive.

Abstract: A method for forming an NiCr seed layer based bottom spin valve sensor element having a synthetic antiferromagnet pinned (SyAP) layer and a capping layer comprising either a single specularly reflecting nano-oxide layer (NOL) or a bi-layer comprising a non-metallic layer and a specularly reflecting nano-oxide layer and the sensor element so formed. The method of producing these sensor elements provides elements having higher GMR ratios and lower resistances than elements of the prior art.

Abstract: A method for forming a bottom spin valve sensor having a synthetic antiferromagnetic pinned (SyAP) layer, antiferromagnetically coupled to a pinning layer, in which one of the layers of the SyAP is formed as a three layer lamination that contains a specularly reflecting oxide layer of FeTaO. The sensor formed according to this method has an extremely high GMR ratio and exhibits good pinning strength.

Abstract: A method for forming an NiCr seed layer based bottom spin valve sensor element having a synthetic antiferromagnet pinned (SyAP) layer and a capping layer comprising either a single specularly reflecting nano-oxide layer (NOL) or a bi-layer comprising a non-metallic layer and a specularly reflecting nano-oxide layer and the sensor element so formed. The method of producing these sensor elements provides elements having higher GMR ratios and lower resistances than elements of the prior art.

Abstract: A method for forming a bottom spin valve sensor having a synthetic antiferromagnetic pinned (SyAP) layer, antiferromagnetically coupled to a pinning layer, in which one of the layers of the SyAP is formed as a three layer lamination that contains a specularly reflecting oxide layer of FeTaO. The sensor formed according to this method has an extremely high GMR ratio and exhibits good pinning strength.

Abstract: A spin valve type magnetoresistance effect film comprises a magnetic multilayered film including a non-magnetic metal layer, a ferromagnetic layer formed on one surface of the non-magnetic metal layer, a soft magnetic layer formed on the other surface of the non-magnetic metal layer, and an antiferromagnetic layer which is formed on a surface of the ferromagnetic layer remote from a surface thereof abutting the non-magnetic metal layer so as to pin a direction of magnetization of the ferromagnetic layer. The antiferromagnetic layer contains oxygen as impurities and a concentration of oxygen contained in the antiferromagnetic layer is set to 1 to 2,000 atomic ppm. With this arrangement, there can be provided a magnetoresistance effect film having a high-quality antiferromagnetic layer which is excellent in thermal stability, sufficiently high in blocking temperature and highly excellent in pinning effect.

Abstract: According to the present invention, a magnetic multilayered film includes an oxide antiferromagnetic layer, a pinned ferromagnetic layer which is pinned by the oxide antiferromagnetic layer, a non-magnetic metal layer and a free ferromagnetic layer which are stacked on a substrate in order. A surface roughness Ra of the oxide antiferromagnetic layer at the side of the pinned ferromagnetic layer is set to no greater than 0.6 nm, and a crystal grain size D of the oxide antiferromagnetic layer is set to a value in the range of 10 to 40 nm. Thus, the magnetic multilayered film has the large exchange-coupling magnetic field and MR ratio and MR sensitivity. The magnetic multilayered film may be applied to a magnetoresistance effect element which may also applied to a magnetoresistance device, such as, a magnetoresistance effect type head. The magnetoresistance effect element having such a magnetic multilayered film is capable of obtaining high outputs.

Abstract: This invention is directed to a ferromagnetic tunnel junction, an MR element and a magnetic head. A ferromagnetic tunnel junction is constituted by sequentially laminating a first ferromagnetic film, an insulating film and a second ferromagnetic film. These are laminated on an appropriate insulating substrate. The present invention is characterized in that the barrier potential of the insulating film is set within a range of 0.5 to 3 eV. A ferromagnetic tunnel junction with which a high MR ratio can be achieved with good reproduction characteristics is provided.

Abstract: A magnetic recording medium is provided comprising a flexible substrate and a ferromagnetic metal thin film layer on the substrate primarily comprising cobalt. When coercive force is measured by changing the measuring direction in a plane defined by a longitudinal direction of the substrate and a direction normal to the major surface of the substrate, the following relationship is met:(Hc.sub.max -Hc.sub.min)/Hc(O).ltoreq.0.9where Hc.sub.max is the maximum of the coercive force, Hc.sub.min is the minimum of the coercive force, and Hc(O) is a coercive force in the longitudinal direction of the substrate. The medium has in average at least 10.sup.5 /a.sup.2 protrusions per square millimeter of the surface, the protrusions having a height of 30 to 300 .ANG., where a is the distance as expressed in .mu.m of a gap in a magnetic head across which the medium is passed for recording and reproducing operation. The filling ratio of the ferromagnetic metal thin film layer is at least 0.7.

Abstract: A magnetic recording medium exhibiting improved running stability and durability is obtained by covering a magnetic layer of ferromagnetic metal thin film with a topcoat layer comprising at least one fatty acid ester having a melting point of from -20.degree. C. to 30.degree. C. and at least one compound containing a group having a radiation sensitive unsaturated double bond and a group having a fluorine substituted alkyl group.