Abstract: A method of manufacturing a magnetic head includes the steps of: fabricating a substructure in which pre-head portions are aligned in a plurality of rows by forming components of a plurality of magnetic heads on a single substrate; and fabricating the plurality of magnetic heads by separating the pre-head portions from one another through cutting the substructure. In the step of fabricating the substructure, the resistance of an MR film that will be formed into an MR element by undergoing lapping later is detected to determine the target position of the boundary between a track width defining portion and a wide portion of a pole layer based on the resistance detected, and the pole layer is thereby formed. In the step of fabricating the magnetic heads, the surface formed by cutting the substructure is lapped such that the MR film is lapped and the resistance thereof thereby reaches a predetermined value.

Abstract: A method of measuring temperature of a TMR element includes a step of obtaining in advance a temperature coefficient of element resistance of a discrete TMR element that is not mounted on an apparatus, by measuring temperature versus element resistance value characteristic of the discrete TMR element in a state that a breakdown voltage is intentionally applied to the discrete TMR element and a tunnel barrier layer of the discrete TMR element is brought into a stable conductive state, a step of bringing a tunnel barrier layer of a TMR element actually mounted on the apparatus into a stable conductive state by intentionally applying the breakdown voltage to the mounted TMR element having the same structure as that of the discrete TMR element whose temperature coefficient has been measured, a step of measuring an element resistance value of the mounted TMR element with the tunnel barrier layer that has been brought into a stable conductive state, and a step of obtaining a temperature corresponding to the measure

Abstract: A method of manufacturing a thin-film magnetic head including forming the first shield layer; forming the magnetoresistive device, carried out after forming the first shield layer, a heat treatment providing exchange coupling between the ferromagnetic layer and the antiferromagnetic layer so as to magnetize the ferromagnetic layer in a predetermined direction; forming the domain control layer so as to hold the magnetoresistive device in a track width direction; magnetizing the domain control layer in a direction yielding a magnetic field in the same direction as with a magnetic field received by the ferromagnetic layer upon exchange-coupling with the antiferromagnetic layer, forming the second shield layer, carried out after magnetizing the domain control layer, and remagnetizing the domain control layer in a direction yielding the longitudinal bias magnetic field, carried out after forming the second shield layer.

Abstract: A technique includes forming overlaying magnetic metal layers over a semiconductor substrate. The technique includes forming at least one resistance layer between the magnetic metal layers.

Abstract: A method of manufacturing a GMR, TMR or CPP GMR sensor having a smooth interface between magnetic and non-magnetic layers to improve sensor performance by exposing a layer to a low energy ion beam prior to depositing a subsequent layer.

Abstract: Spin-torque devices are based on a combination of giant magnetoresistance (GMR) and tunneling magnetoresistance (TMR) effects. The basic structure has various applications, including amplifiers, oscillators, and diodes. For example, if the low-magnetoresistance (GMR) contact is biased below a critical value, the device may function as a microwave-frequency selective amplifier. If the GMR contact is biased above the critical value, the device may function as a microwave oscillator. A plurality of low- and high-magnetoresistance contact pairs may be induced to oscillate in a phase-locked regime, thereby multiplying output power. The frequency of operation of these devices will be tunable by the external magnetic field, as well as by the direct bias current, in the frequency range between 10 and 100 GHz. The devices do not use semiconductor materials and are expected to be exceptionally radiation-hard, thereby finding application in military nanoelectronics.

Abstract: A magnetic sensing element includes a free magnetic layer having a three-layer structure including a first enhancement layer in contact with a nonmagnetic material layer, a second enhancement layer, and a low-coercivity layer. The second enhancement layer has a lower magnetostriction coefficient ? than the first enhancement layer. If such an enhancement layer having a bilayer structure is used, rather than a known monolayer structure, and the second enhancement layer has a lower magnetostriction coefficient ? than the first enhancement layer, the rate of change in magnetoresistance of the magnetic sensing element can be increased with no increase in the magnetostriction coefficient ? of the free magnetic layer.

Abstract: A method for detecting an impending failure of a disk drive system. The method includes monitoring a signal from a magnetoresistive sensor for the presence of a negative signal spike. A negative signal spike can indicate that the carbon overcoat of the magnetic medium has been locally worn off. The resulting localized absence of carbon overcoat causes the magnetoresistive sensor to short to the magnetic medium. This causes a short, abrupt drop in voltage, which can be used as evidence of the localized absence of the carbon overcoat. If such a negative signal spike is detected, the user can be notified of an impending system failure. In addition to, or in lieu of, notifying the user of the impending system failure, the system can be automatically de-activated to prevent data loss and/or further damage to the recording system.

Abstract: A compact oscillator in which the oscillation frequency can be adjusted to a desired value is provided. The oscillator includes: a magnetoresistive effect element comprising a pinned layer, a nonmagnetic spacer layer, and a free layer of which magnetization direction is changeable that are stacked in that order, a magnetization direction of the pinned layer being substantially fixed along a direction perpendicular to a stack direction; a bias magnetic field application unit for applying a bias magnetic field to the free layer in a direction that is perpendicular to the stack direction and is different from the magnetization direction of the pinned layer; and an adjusting magnetic field application unit for applying an adjusting magnetic field to the free layer in a direction that is perpendicular to the stack direction and is different from the direction of the bias magnetic field.

Abstract: An apparatus includes a thermally insulating substrate, an energy absorbing layer on the thermally insulating substrate, and a flash annealed magnetic layer on the energy absorbing layer. The flash annealed magnetic layer may be configured for data storage. A method includes providing a thermally insulating substrate, depositing an energy absorbing layer on the thermally insulating substrate, depositing a magnetic layer on the energy absorbing layer, and flash annealing the magnetic layer.

Abstract: A magnetoresistance effect element includes a pinned layer having a fixed magnetization direction, a free layer having a magnetization direction variable depending on an external magnetic field, and a nonmagnetic spacer layer disposed between the pinned layer and the free layer. The free layer includes a Heusler alloy layer and a magnetostriction reduction layer made of a 4th group element, a 5th group element, or a 6th group element.

Abstract: A thin film magnetic head is disclosed that is capable of preventing the contact between an element portion and a recording medium and a variation in the amount of protrusion of the element portion. A thin film magnetic head includes: a reproducing element; a recording element that is formed on the reproducing element; a heater that is supplied with power and generates heat to expand at least one of the reproducing element and the recording element such that the reproducing element and/or the recording element protrude toward a recording medium; and a temperature correcting resistor that is connected in parallel to the heater and has a negative resistance temperature coefficient.

Abstract: The magnetoresistance effect element includes: a magnetization fixing layer; a barrier layer formed on the magnetization fixing layer; and a free layer formed on the barrier layer. The method of producing the magnetoresistance effect element comprises the steps of: forming the magnetization fixing layer on a substrate; forming a metal film as the barrier layer, wherein one part of the metal film on the magnetization fixing layer side is in an amorphous state or a refined crystal state and the other part thereof on the other side is in a crystal state; natural-oxidizing the metal film in an oxidizing atmosphere; forming the free layer on the oxidized metal layer.

Abstract: Provided are a CCP (current confined path)-CPP (current-perpendicular-to-plane) type giant magneto-resistance (GMR) element having a giant magneto-resistance ratio in a low resistance region (a region of not more than 1 ohm per square micrometer) and a magnetic sensor using this GMR element. The CCP-CPP type GMR element A has a laminated structure of an anti-ferromagnetic layer, a magnetization pinned layer, an intermediate layer and a magnetization free layer, and is formed to have a construction in which a current flows perpendicularly to a film plane. By using an ultrathin magnesium oxide layer having micropores that is preferentially oriented in the (001) direction as the intermediate layer, the magneto-resistance ratio is enhanced, because a current flowing from the magnetization free layer to the magnetization pinned layer (or in the opposite direction) is confined by the metal in the micropores.

Abstract: A magnetic head testing apparatus having the function of evaluating pin holes in a tunnel barrier layer of a TMR element by a non destructive inspection is disclosed. The testing apparatus comprises a temperature control unit which sets a circumferential temperature of a TMR element, a bias electric current control unit which applies an electric current for measuring a resistance value, an element resistance measuring unit and a CPU which calculates a temperature coefficient. The CPU determines a pin hole state in the tunnel barrier layer based on the temperature coefficient.

Abstract: Magnetoresistive (MR) sensors are disclosed having mechanisms for reducing edge effects such as Barkhausen noise. The sensors include a pinned layer and a free layer with an exchange coupling layer adjoining the free layer, and a ferromagnetic layer having a fixed magnetic moment adjoining the exchange coupling layer. The exchange coupling layer and ferromagnetic layer form a synthetic antiferromagnetic structure with part of the free layer, providing bias that reduces magnetic instabilities at edges of the free layer. Such synthetic antiferromagnetic structures can provide a stronger bias than conventional antiferromagnetic layers, as well as a more exactly defined track width than conventional hard magnetic bias layers. The synthetic antiferromagnetic structures can also provide protection for the free layer during processing, in contrast with the trimming of conventional antiferromagnetic layers that exposes if not removes part of the free layer.

Abstract: A pair of domain control layers are disposed on both sides of the track width direction of the MR film so as to be separated from each other such that the MR film is held therebetween, and apply a longitudinal magnetic field to the MR film (free layer). The MR film is flanked by the domain control layers, each including a layer structure constituted by a base layer, a ferromagnetic layer, and a hard magnetic layer. The base layer causes the hard magnetic layer to have a magnetization direction aligning with an in-plane direction, so as to enhance the coercive force of the hard magnetic layer.

Abstract: A magnetic sensing element includes a composite film, a lower shield layer, and a lower electrode layer and an upper electrode layer for supplying a current perpendicular to the composite film. The composite film has an antiferromagnetic layer, a pinned magnetic layer, a nonmagnetic layer, and a free magnetic layer. The composite film has a top face and two side faces in a track width direction. Each of the two side faces has a bent position. The angle defined by the side face below the bent position and the top face is larger than the angle defined by the side face above the bent position and the top face. The bent portion preferably lies on the lower electrode layer or the lower shield layer.

Abstract: An exchange coupling film including an antiferromagnetic layer and a ferromagnetic layer in contact with the antiferromagnetic layer so as to generate an exchange coupling magnetic field is provided. A PtMn alloy is used as the material of the antiferromagnetic layer. Crystal planes of the antiferromagnetic layer and the ferromagnetic layer preferentially aligned parallel to the interface are crystallographically identical and crystallographically identical axes lying in these crystal planes are oriented, at least partly, in different directions between the antiferromagnetic layer and the ferromagnetic layer. Thus, a proper order transformation occurs in the antiferromagnetic layer as a result of heat treatment and an increased exchange coupling magnetic field can be obtained.

Abstract: A PtMn alloy film known as an antiferromagnetic material having excellent corrosion resistance is used for an antiferromagnetic layer. However, an exchange coupling magnetic field is decreased depending upon the conditions of crystal grain boundaries. Therefore, in the present invention, the crystal grain boundaries formed in an antiferromagnetic layer (PtMn alloy film) and the crystal grain boundaries formed in a ferromagnetic layer are made discontinuous in at least a portion of the interface between both layers. As a result, the antiferromagnetic layer can be appropriately transformed to an ordered lattice by heat treatment to obtain a larger exchange coupling magnetic field than a conventional element.

Abstract: A magnetic head testing apparatus having the function of evaluating pin holes in a tunnel barrier layer of a TMR element by a non destructive inspection is disclosed. The testing apparatus comprises a temperature control unit which sets a circumferential temperature of a TMR element, a bias electric current control unit which applies an electric current for measuring a resistance value, an element resistance measuring unit and a CPU which calculates a temperature coefficient. The CPU determines a pin hole state in the tunnel barrier layer based on the temperature coefficient.

Abstract: A thin-film magnetic head has an inductive write head element including an upper core layer with a front end section magnetically coupling with an upper magnetic pole, a lower core layer with a front end section magnetically coupling with a lower magnetic pole, a coil conductor formed to pass between the upper core layer and the lower core layer, and an coil insulation layer for sandwiching the coil conductor. At least one thermal diffusion layer with a good thermal conductivity is formed on the coil insulation layer at an outside region of the upper core layer, or at least one thermal diffusion layer is formed at an outside region of the upper core layer to contact with a part of the coil conductor or to constitute a part of the coil conductor.

Abstract: A method and apparatus of a spin-type magnetoresistance sensor having a free and pinned magnetic layer stacked with a non-magnetic interposed layer are disclosed.