Abstract: A TMR element includes a lower magnetic layer, an upper magnetic layer, and a tunnel barrier layer of crystalline insulation material sandwiched between the lower magnetic layer and the upper magnetic layer. The lower magnetic layer includes a first magnetic layer and a second magnetic layer sandwiched between the first magnetic layer and the tunnel barrier layer. The second magnetic layer is formed from a magnetic material containing at least one of Fe, Co and Ni.

Abstract: The exchange coupled film according to the present invention comprises a buffer layer including a laminate in which an amorphous layer and a hafnium layer are laminated in that order, an antiferromagnetic layer laminated on the hafnium layer of the buffer layer via an intermediate layer with a thickness of at least 2 nm, and a pinned magnetic layer laminated on the antiferromagnetic layer.

Abstract: A method for testing an MR element includes a step of obtaining a ferromagnetic resonance frequency f0 of the MR element to be tested by applying an external magnetic field in a track-width direction to the MR element, a step of calculating a stiffness magnetic field Hstiff from the obtained ferromagnetic resonance frequency f0 using a predetermined formula, a step of obtaining a relationship of a stiffness magnetic field Hstiff with respect to an external magnetic field applied in the track-width direction from the applied external magnetic field and the calculated stiffness magnetic field Hstiff, a step of obtaining a uniaxial anisotropic magnetic field Hk of a free layer of the MR element from the obtained relationship of the stiffness magnetic field Hstiff with respect to the external magnetic field applied, and a step of judging whether the MR element is good product or not by comparing the obtained uniaxial anisotropic magnetic field Hk with a predetermined threshold.

Abstract: A method for producing a thin film magnetic head including a magnetoresistive effect element (MR element) that has a magnetic sensor multi-layered film with a polygonal shape such that a vertex angle faces an air bearing surface (ABS) and a tip of the vertex angle is cut when the magnetic sensor multi-layered film is viewed from an X-Y plane that is parallel to a plane of a lower shield electrode layer includes a step for stopping a lapping process by using a measurement point in which a resistance value is steeply increased while the lapping face is gradually approaching the vertex angle of polygonal shape by lapping from the ABS side. Therefore, an excellent effect in which an ultra narrow track width that exceeds limits of photolithography technology can be securely and constantly formed is obtained.

Abstract: A reproducing method of reproducing magnetic information written in each of bits of a recording medium using a magnetic head having a reading element configured to measure external magnetic field intensity includes moving, measuring and specifying steps. In the moving step, the magnetic head moves to a position where the reading element covers two bits, one bit having known magnetic information, the other bit being adjacent to the one bit and having unknown magnetic information. In the measuring step, the reading element measures magnetic field intensity coming from the recording medium. In the specifying step, magnetic information of the bit having the unknown magnetic information is specified based on the magnetic field intensity measured in the measuring step and magnetic information of the bit having the known magnetic information.

Abstract: The thin-film magnetic head of the invention comprises a magneto-resistive effect device including a multilayer film and a bias mechanism portion including a bias magnetic field-applying layer formed on each widthwise end of the multilayer film. When the magneto-resistive effective device including a multilayer film and the bias mechanism portion are viewed in plane on their own, the uppermost extremity of the rear end of the magneto-resistive effect device and the uppermost extremity of the rear end of the bias mechanism portion lie at substantially the same depth-wise position, and the rear slant of the bias mechanism portion is gentler in gradient than the rear slat of the magneto-resistive effect device. It is thus possible just only to facilitate the fabrication of the device but also to achieve several advantages of being a lower rate of occurrence of noise, higher reliability and higher yields.

Abstract: The estimation method of the invention for estimating the deteriorations of a magneto-resistive effect device by heat shocks involves applying heat shocks by laser irradiation to a structure including a thin-film magnetic head comprising a magneto-resistive effect device to propagate them to the magneto-resistive effect device, thereby causing the deteriorations of the magneto-resistive effect device. Thus, (1) the deterioration mode phenomenon of “local overheating plus vibration” can be imitated in a simple yet very approximate state so that a device likely to undergo characteristics deteriorations due to the thermal asperity problem can be detected early at an initial fabrication process stage, and (2) what specifications a head device structure less likely to offer the thermal asperity problem is in can be judged at a product development stage.

Abstract: A magnetic detector includes a magnetoresistive element and an impact sensor. The magnetoresistive element has a plurality of element-constituent layers that are stacked and include a free layer having a magnetization direction that changes in response to a magnetic field to be detected by the magnetic detector. The impact sensor has a plurality of sensor-constituent layers that are made of materials the same as those of the element-constituent layers and stacked in the same order as the element-constituent layers. The plurality of sensor-constituent layers include an impact detecting layer corresponding to the free layer and having a magnetization direction that changes by an inverse magnetostrictive effect in response to distortion created in the impact detecting layer by an impact received by the magnetic detector. The impact detecting layer exhibits a greater amount of change in magnetization direction when the magnetic detector receives an impact, compared with the free layer.

Abstract: An MR element includes a lower shield layer, a magnetization free function part stacked on the lower shield layer, an upper shield layer stacked on the magnetization free function part, a nonmagnetic intermediate layer stacked on a surface, that is opposite to a magnetically sensitive surface, of the magnetization free function part, and a magnetization fixed function part stacked on the nonmagnetic intermediate layer. The nonmagnetic intermediate layer and the magnetization fixed function part are formed only within an outer region of the magnetization free function part, located opposite side to the magnetically sensitive surface.

Abstract: A method for testing an MR element includes a step of obtaining a ferromagnetic resonance frequency f0 of the MR element to be tested by applying an external magnetic field in a track-width direction to the MR element, a step of calculating a stiffness magnetic field Hstiff from the obtained ferromagnetic resonance frequency f0 using a predetermined formula, a step of obtaining a relationship of a stiffness magnetic field Hstiff with respect to an external magnetic field applied in the track-width direction from the applied external magnetic field and the calculated stiffness magnetic field Hstiff, a step of obtaining a uniaxial anisotropic magnetic field Hk of a free layer of the MR element from the obtained relationship of the stiffness magnetic field Hstiff with respect to the external magnetic field applied, and a step of judging whether the MR element is good product or not by comparing the obtained uniaxial anisotropic magnetic field Hk with a predetermined threshold.

Abstract: The exchange coupled film according to the present invention comprises a buffer layer including a laminate in which an amorphous layer and a hafnium layer are laminated in that order, an antiferromagnetic layer laminated on the hafnium layer of the buffer layer via an intermediate layer with a thickness of at least 2 nm, and a pinned magnetic layer laminated on the antiferromagnetic layer.

Abstract: A magnetoresistance effect element comprises: a pair of magnetic layers whose magnetization directions form a relative angle therebetween that is variable depending on an external magnetic field; and a crystalline spacer layer sandwiched between the pair of magnetic layers; wherein sense current may flow in a direction that is perpendicular to a film plane of the pair of magnetic layers and the spacer layer. The spacer layer includes a crystalline oxide, and either or both magnetic layers whose magnetization direction is variable depending on the external magnetic field has a layer configuration in which a CoFeB layer is sandwiched between a CoFe layer and a NiFe layer and is positioned between the spacer layer and the NiFe layer.

Abstract: The invention provides a method for fixing up the deterioration of a magneto-resistive effect device. A hard disk system is provided in it with a head heating means for heating a thin-film magnetic head, and by that head heating means, a defective site of the magneto-resistive effect device, which occurs as the hard disk system is in operation and is confined in a quasi-stable state, is fixed up in such a way as to return back to its own normal stable state. Thus, the deteriorated site of the magneto-resistive effect device (reproducing device) in the thin-film magnetic head, which is caused by the so-called thermal asperity as the hard disk system is in operation, is fixed up while it remains built in the hard disk system, i.e., without dismantling the hard disk system.

Abstract: The estimation method of the invention for estimating the deteriorations of a magneto-resistive effect device by heat shocks involves applying heat shocks by laser irradiation to a structure including a thin-film magnetic head comprising a magneto-resistive effect device to propagate them to the magneto-resistive effect device, thereby causing the deteriorations of the magneto-resistive effect device. Thus, (1) the deterioration mode phenomenon of “local overheating plus vibration” can be imitated in a simple yet very approximate state so that a device likely to undergo characteristics deteriorations due to the thermal asperity problem can be detected early at an initial fabrication process stage, and (2) what specifications a head device structure less likely to offer the thermal asperity problem is in can be judged at a product development stage.

Abstract: The thin-film magnetic head of the invention comprises a magneto-resistive effect device including a multilayer film and a bias mechanism portion including a bias magnetic field-applying layer formed on each widthwise end of the multilayer film. When the magneto-resistive effective device including a multilayer film and the bias mechanism portion are viewed in plane on their own, the uppermost extremity of the rear end of the magneto-resistive effect device and the uppermost extremity of the rear end of the bias mechanism portion lie at substantially the same depth-wise position, and the rear slant of the bias mechanism portion is gentler in gradient than the rear slat of the magneto-resistive effect device. It is thus possible just only to facilitate the fabrication of the device but also to achieve several advantages of being a lower rate of occurrence of noise, higher reliability and higher yields.

Abstract: A TMR element includes a lower magnetic layer, an upper magnetic layer, and a tunnel barrier layer of crystalline insulation material sandwiched between the lower magnetic layer and the upper magnetic layer. The lower magnetic layer includes a first magnetic layer and a second magnetic layer sandwiched between the first magnetic layer and the tunnel barrier layer. The second magnetic layer is formed from a magnetic material containing at least one of Fe, Co and Ni.