Tdk Corporation

Other

Oki Electric Industry Co., Ltd.

Teruya Shinjo

Satoru Araki

Koji Shimazawa

Masashi Sano

Yoshihiro Tsuchiya

Haruyuki Morita

Daisuke Miyauchi

Noriaki Kasahara

Shuxiang Li

Olivier Redon

Kiyoshi Noguchi

Manabu Ohta

Osamu Shinoura

Takumi Uesugi

Yuuji Honda

Taro Oike

Yoshihito Shimazaki

Yuuichi Sato

Jijun Sun

Isamu Sato

Tsuyoshi Umehara

Tetsuro Sasaki

Nozomu Hachisuka

Yuichi Sato

Shigeru Ono

Kenichiro Hosoda

Yoshikazu Narumiya

Eiichi Omata

Takuto Moriguchi

Seiji Mitani

Toshiyuki Shima

Koki Takanashi

Yasuyuki Yamamoto

Kiyomi Yasui

Provided are a magnetic transducer capable of increasing a resistance change and obtaining an appropriate coercive force, a thin film magnetic head, a method of manufacturing a magnetic transducer and a method of manufacturing a thin film magnetic head. A stack, a spin valve film has a stacked structure comprising a first soft magnetic layer, a second soft magnetic layer, a nonmagnetic metal layer, a ferromagnetic layer, an antiferromagnetic layer and a protective layer which are stacked in sequence on an underlying layer. Electrical resistance is changed in accordance with a relative angle between the orientation of magnetization of the ferromagnetic layer and the orientation of magnetization of the first and second soft magnetic layers. A soft magnetic interlayer having magnetism and the electrical resistance higher than the electrical resistance of the first soft magnetic layer is formed in the first soft magnetic layer. When a current flows through the stack, electrons are reflected by the surface of the soft magnetic interlayer and thus a path for the electrons is narrowed. Therefore, a rate of resistance change is increased.

Magnetic transducer, thin film magnetic head and method of manufacturing the same

A tunnel magnetoresistive effective element has a ferromagnetic tunnel effective film with a free layer, a pinned layer and a tunnel barrier layer sandwiched between the free layer and the pinned layer, a magnetic bias means, a first conductive layer, and a second conductive layer. The magnetic bias means apply a bias magnetic field to the free layer of the ferromagnetic tunnel effective film. The first conductive layer and the second conductive layer generate magnetic fields having the same direction as that of the bias magnetic field through a sense current therein to reinforce the bias magnetic field.

Tunnel magnetoresistive effective element, and a thin film magnetic head, a magnetic head device and a magnetic disk drive device using same

Provided are a magnetic transducer having good thermal stability, a thin film magnetic head, a method of manufacturing a magnetic transducer and a method of manufacturing a thin film magnetic head. A stack of an MR element has a stacked structure comprising an underlayer, a first soft magnetic layer, a second soft magnetic layer, a nonmagnetic layer, a ferromagnetic layer, an antiferromagnetic layer and a capping layer, which are stacked in this order on the underlayer. The ferromagnetic layer is divided into a bottom layer and a top layer in the direction of stack. A ferromagnetic interlayer having magnetism and having higher electrical resistance than the electrical resistance of the ferromagnetic layer is formed between the bottom layer and the top layer. The ferromagnetic interlayer magnetically integrates the bottom layer with the top layer and limits a path for electrons moving through the stack, thereby improving the rate of resistance change. Furthermore, the ferromagnetic interlayer contains, as an additive, at least one element in a group consisting of Mn, Cr, Ni, Cu, Rh, Ir and Pt and thus prevents heat deterioration in the stack.

Magnetic transducer, thin film magnetic head, method of manufacturing magnetic transducer and method of manufacturing thin film magnetic head

A TMR element includes: a free layer formed on a lower gap layer; a tunnel barrier layer formed on the free layer; and a pinned layer formed on the tunnel barrier layer. The pinned layer and the tunnel barrier layer have sidewalls formed through etching. The TMR element further comprises a deposition layer made of a material that is separated by etching and deposits on the sidewalls and undergoes oxidation.

Methods of manufacturing a tunnel magnetoresistive element, thin-film magnetic head and memory element

In a thin film magnetic head device including a reading giant magneto-resistive thin film magnetic head element whose electric equivalent circuit is expressed by a series circuit of an equivalent voltage source and a series resistor Rand a parallel capacitor C connected in parallel with said series circuit, inductor L is connected in series with said series resistor Rand a parallel resistor R is connected in series with said parallel capacitor C. The coil L and parallel capacitor C are set such that an angular frequency &#x3c9;=1/(LC), an angular frequency &#x3c9;=1/CR and an angular frequency &#x3c9;=1/CRsatisfy conditions of &#x3c9;&#x3e;&#x3c9;and &#x3c9;&#x3e;&#x3c9;, preferably &#x3c9;&#x3e;&#x3e;&#x3c9;and &#x3c9;&#x3e;&#x3e;&#x3c9;to extend a frequency characteristic toward a high frequency range.

Thin film magnetic head device

On a substrate at a temperature of 120 to 240&deg; C., Fe and Pt monatomic layers are alternately laminated. The magnetic multilayer film obtained by such a method has an L1 ordered structure so as to exhibit a high magnetic anisotropy energy constant, a (001) surface parallel to the substrate surface, and a high perpendicular magnetic anisotropy, while its coercive force in a direction perpendicular to the substrate surface and the squareness ratio of its magnetization curve in a direction perpendicular to the substrate surface are large, so that it is usable as a magnetic recording film for a magnetic recording medium and the like. Also, since the magnetic multilayer film is formed while the substrate temperature is 120 to 240&deg; C., the temperature load on the substrate or the like is lowered as compared with conventional making methods in which the substrate temperature is about 500&deg; C.

Method of manufacturing magnetic multilayer film, method of manufacturing magnetic recording medium, magnetic multilayer film and magnetic recording medium

A method of manufacturing a ferromagnetic tunnel junction element, having an insulating film, a first ferromagnetic film and a second ferromagnetic film, including a step of turning the ferromagnetic tunnel junction element on electricity for a given period before a practical operation of the ferromagnetic tunnel junction element, so that a resistance of the insulating film is stabilized.

Method for stabilizing properties of a ferromagnetic tunnel junction element

An object of the invention is to provide a thin film magnetic head and a magnetic transducer, which can obtain resistance properties adaptable to ultra-high-density recording. The thin film magnetic head has a stack including a plurality of magnetic layers stacked alternately with a plurality of nonmagnetic layers. The stack is divided into a first region and a second region in a direction of stacking. The first region comprises a projecting portion projecting toward a magnetic medium, an extending portion extending in the direction opposite to the projecting portion, and a pair of wide portions widened in the direction perpendicular to the direction in which the extending portion extends. An end surface of the projecting portion is exposed to the outside and faces the magnetic medium. Thus, the end surface functions as a magnetic field capturing portion for capturing a signal magnetic field of the magnetic medium. The stack has the projecting portion, and the projecting portion functions as the magnetic field capturing portion. Thus, the number of layers of the stack can be increased without increasing a length of a surface facing the magnetic medium. Therefore, the rate of resistance change and the resistance can be increased.

Thin film magnetic head and magnetic transducer

A magnetic tunnel junction device and method for making same is provided. A first ferromagnetic portion is provided. A barrier is provided on the first ferromagnetic portion. The barrier includes a first barrier portion on the first ferromagnetic portion. The first barrier portion is oxidized. After oxidizing, a second barrier portion is provided on the first barrier portion. The second barrier may be oxidized or annealed. A second ferromagnetic portion is provided on the barrier. The barrier of the resultant device has a reduced number of pinholes, minimizing the amount of the non-tunnel current, and an improved symmetry of electrical properties. This leads to advantages in performance characteristics and mass-production of the device.

Magnetic tunnel junction read head devices having a tunneling barrier formed by multi-layer, multi-oxidation processes

A magnetoresistive (MR) head including, for example, a spin valve (SV) MR element having a sense current passing through the SV in a current-perpendicular-to-the-plane (CPP) mode. A free layer of the SV is transversely biased by a magnetostatic coupling field from an in-stack transverse bias layer. The transverse bias layer is separated from the free layer by a nonmagnetic high resistive spacer layer, which can cause strong spin memory loss and also provide a longitudinal biasing to the free layer of the SV. An out of stack longitudinal bias arrangement may alternatively be provided to impart a longitudinal bias to the free layer. The SV MR element comprises a MR promoting (MRP) layer either within in or adjacent to the free layer or the pinned layer This MR head structure provides enhanced linearity of the response to the magnetic field being sensed.

Current perpendicular-to-the-plane magnetoresistance read head

A current perpendicular-to-the-plane magnetoresistance (CPP-MR) device includes a first magnetic shield, a second magnetic shield, and a spin valve structure. The first and second magnetic shields are formed of an electrically conductive and magnetically shielding material. A read gap is defined between the first and second magnetic shields, and the spin valve structure is disposed between the first and second magnetic shields. The spin valve structure is electrically connected and magnetically separated from the first and second magnetic shields such that the first and second magnetic shields act as electrical contact leads.

Dual spin valve CPP MR with flux guide between free layers thereof

A ferromagnetic tunnel effective film has a free layer, and a pinned layer and a tunnel barrier layer sandwiched between the free layer and the pinned layer. A bias magnetic field-inductive layer applies a given magnetic field to the free layer, and has its larger width than that of the ferromagnetic tunnel effective film in the bias magnetic field direction. A flux guide layer is stacked with the bias magnetic field-inductive layer, and magnetically combined with the free layer. One end of the flux guide layer constitutes a flux probe portion having its smaller width than that of the bias magnetic field-inductive layer and projecting from the ends of the bias magnetic field-inductive layer.

Tunnel magnetoresistive effective element, a thin film magnetic head, a magnetic head device and a magnetic disk drive device

Magnetic transducer with interlayer thin-film magnetic head and method of manufacturing thereof

Provided are a magnetic transducer having a higher rate of resistance change and a larger magnitude of resistance change and having better stability of properties, and a thin film magnetic head. A stack of an MR element has a stacked structure comprising an underlayer, an antiferromagnetic layer, a ferromagnetic layer, a first nonmagnetic layer, a first soft magnetic layer, a second soft magnetic layer, a second nonmagnetic layer and a high-resistance layer, which are stacked in sequence on the underlayer. The orientation of magnetization of the ferromagnetic layer is fixed by exchange coupling between the ferromagnetic layer and the antiferromagnetic layer. The orientations of magnetizations of the first soft magnetic layer and the second soft magnetic layer change according to an external magnetic field. Electrical resistance of the stack changes according to a relative angle between the orientations of the magnetizations of the first soft magnetic layer and the second soft magnetic layer and the orientation of the magnetization of the ferromagnetic layer. The high-resistance layer has higher electrical resistance than electrical resistance of the second nonmagnetic layer. The second nonmagnetic layer and the high-resistance layer are provided on the side of the second soft magnetic layer opposite to the first nonmagnetic layer. Thus, the rate of resistance change and the magnitude of resistance change can be increased, and furthermore stability of properties can be improved.

Magnetic transducer with a higher rate and larger magnitude of resistance change

Provided are a magnetic transducer and a thin film magnetic head having good thermal stability and capable of obtaining a high exchange coupling magnetic field, a method of manufacturing a magnetic transducer and a method of a manufacturing a thin film magnetic head. An MR element has a stack having a stacked structure comprising an underlayer, a crystal-growth inhibitor layer, a first soft magnetic layer, a second soft magnetic layer, a nonmagnetic layer, a ferromagnetic layer, an antiferromagnetic layer and a cap layer, which are stacked in sequence. The ferromagnetic layer has an inner ferromagnetic layer, a coupling layer and an outer ferromagnetic layer, which are stacked in this order on the nonmagnetic layer. The crystal-growth inhibitor layer inhibits crystal growth of the layers formed on the crystal-growth inhibitor layer, thereby limiting an average in-surface particle diameter of the inner ferromagnetic layer to within the range of from 3 nm to 8 nm inclusive, so that an interface between the coupling layer and the inner ferromagnetic layer becomes flattened.

Growing community of inventors

Tokyo, Japan

Satoru Araki