Using A Permanent Magnet Patents (Class 360/327.31)
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Patent number: 9557392Abstract: Integrated magnetometer comprising a plurality of multilayer magnetoresistive sensors deposited on a surface, called the top surface, of a substantially planar substrate, characterized in that said top surface of the substrate has at least one cavity or protuberance provided with a plurality of inclined faces, and in that at least four said magnetoresistive sensors are placed on four said magnetoresistive sensors are placed on four said inclined faces, having different orientations and opposite one another in pairs, each sensor being sensitive to one component of an external magnetic field parallel to that face on which it is placed. Process for manufacturing such a magnetometer.Type: GrantFiled: January 28, 2011Date of Patent: January 31, 2017Assignees: Centre National de la Recherche Scientifique, Commissariat a l'Energie Atomique et aux Energies AlternativesInventors: Alain Schuhl, Gilles Gaudin, Philippe Sabon, Pierre-Jean Zermatten, François Montaigne
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Patent number: 9324935Abstract: Provided is an information storage element comprising a first layer, an insulation layer coupled to the first layer, and a second layer coupled to the insulation layer opposite the first layer. The first layer has a transverse length that is approximately 45 nm or less, or an area that is approximately 1,600 nm2 or less, so as to be capable of storing information according to a magnetization state of a magnetic material. The magnetization state is configured to be changed by a current. The insulation layer includes a non-magnetic material. The second layer includes a fixed magnetization so as to be capable of serving as a reference of the first layer.Type: GrantFiled: July 17, 2014Date of Patent: April 26, 2016Assignee: Sony CorporationInventors: Kazutaka Yamane, Masanori Hosomi, Hiroyuki Ohmori, Kazuhiro Bessho, Yutaka Higo, Tetsuya Asayama, Hiroyuki Uchida
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Patent number: 8724265Abstract: A magnetoresistive sensor is generally disclosed. Various embodiments of a sensor can have at least a trilayer sensor stack biased with a back biasing magnet adjacent a back of the trilayer sensor. The back biasing magnet, the trilayer sensor stack, or both have substantially trapezoidal shapes to enhance the biasing field and to minimize noise.Type: GrantFiled: January 17, 2013Date of Patent: May 13, 2014Assignee: Seagate Technology LLCInventors: Jiaoming Qiu, Kaizhong Gao, Yonghua Chen, Beverley Craig, Zhongyan Wang, Vladyslav A. Vas'ko
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Patent number: 8243398Abstract: A magneto-resistive (MR) device for reading at least one of a legacy data and a present data magnetically recorded on at least one legacy track and a least one present track, respectively, is provided. The device comprises first and second MR elements, and first, second, and third permanent magnets. The first MR read element is positioned between the first and the second permanent magnets to stabilize the first MR read element while reading the legacy data from the media. The second MR element is positioned adjacent to the second permanent magnet and configured to read the present data from the media. The third permanent magnet is positioned adjacent to the second MR element and opposite to the second permanent magnet. The second and the third permanent magnets cooperate with each other to stabilize the second MR read element while reading the present data from the media.Type: GrantFiled: June 18, 2008Date of Patent: August 14, 2012Assignee: Oracle America, Inc.Inventors: Charles C. Partee, John P. Nibarger
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Patent number: 8107201Abstract: A hard bias structure for biasing a free layer in a MR element within a read head is comprised of a composite hard bias layer having a Co78.6Cr5.2Pt16.2/Co65Cr15Pt20 configuration. The upper Co65Cr15Pt20 layer has a larger Hc value and a thickness about 2 to 10 times greater than that of the Co78.6Cr5.2Pt16.2 layer. The hard bias structure may also include a BCC underlayer such as FeCoMo which enhances the magnetic moment of the hard bias structure. Optionally, the thickness of the Co78.6Cr5.2Pt16.2 layer is zero and the Co65Cr15Pt20 layer is formed on the BCC underlayer. The present invention also encompasses a laminated hard bias structure. The Mrt value for the hard bias structure may be optimized by adjusting the thicknesses of the BCC underlayer and CoCrPt layers. As a result, a larger process window is realized and lower asymmetry output during a read operation is achieved.Type: GrantFiled: March 5, 2010Date of Patent: January 31, 2012Assignee: Headway Technologies, Inc.Inventors: Kunliang Zhang, Yun-Fei Li, Chyu-Jiuh Torng, Chen-Jung Chien
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Patent number: 7835118Abstract: A method and apparatus for detecting the presence of magnetic beads is disclosed. By providing both a static magnetic field and a magnetic field that alternates in the MHz range, or beyond, the bead can be excited into FMR (ferromagnetic resonance). The appearance of the latter is then detected by a magneto-resistive type of sensor. This approach offers several advantages over prior art methods in which the magnetic moment of the bead is detected directly.Type: GrantFiled: May 12, 2010Date of Patent: November 16, 2010Assignee: Headway Technologies, Inc.Inventor: Yuchen Zhou
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Publication number: 20090316309Abstract: A magneto-resistive (MR) device for reading at least one of a legacy data signal and a present data signal magnetically recorded on at least one legacy track and a least one present track, respectively, is provided. The device comprises first and second MR elements, and first, second, and third permanent magnets. The first MR read element is positioned between the first and the second permanent magnets to stabilize the first MR read element while reading the legacy data signal from the media. The second MR element is positioned adjacent to the second permanent magnet and configured to read the present data signal from the media. The third permanent magnet is positioned adjacent to the second MR element and opposite to the second permanent magnet. The second and the third permanent magnets cooperate with each other to stabilize the second MR read element while reading the present data signal from the media.Type: ApplicationFiled: June 18, 2008Publication date: December 24, 2009Applicant: SUN MICROSYSTEMS, INC.Inventors: Charles C. Partee, John P. Nibarger
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Patent number: 7342752Abstract: A magnetoresistive read head includes a magnetoresistive sensor and a bias structure adjacent to the magnetoresistive sensor. The bias structure provides a magnetostatic bias field for the magnetoresistive sensor. The bias structure includes an underlayer, a bias layer over the underlayer, and at least one dusting layer directly below at least one of the underlayer or the bias layer.Type: GrantFiled: January 31, 2004Date of Patent: March 11, 2008Assignee: Western Digital (Fremont), LLCInventors: Wei Zhang, Yingjian Chen, Satoru Araki, Mohamad T Krounbi
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Patent number: 7050274Abstract: Multilayer permanent magnet films comprising at least two permanent magnet layers separated by an interlayer are disclosed. In one embodiment, the multilayer permanent magnet film includes an interlayer deposited on a first permanent magnet layer, a seed layer deposited on the interlayer, and a second permanent magnet layer deposited on the seed layer. The permanent magnet layers may comprise a material such as CoPt, while the seed layer may comprise a material such as TiW. The interlayer may comprise a material such as Ta. The multilayer permanent magnet films possess favorable properties such as high magnetic coercivity (Hc) and high remnant magnetization (MR) at thicknesses which yield high magnetic fields. The films may be used in applications such as current perpendicular to the plane (CPP) magnetic sensors in which the multilayer permanent magnet film is used to magnetically bias the sensor.Type: GrantFiled: December 10, 2001Date of Patent: May 23, 2006Inventors: Michael A. Seigler, Isabel G. Trindade, Paul E. Anderson
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Patent number: 7035061Abstract: A transducing head includes a first bias element, a second bias element, and a magnetoresistive sensor positioned between the first bias element and the second bias element. The first bias element and the second bias element are each formed of a permanent magnet material having a remanent magnetic moment in a range of about 200 to about 800 emu/cm3. In a preferred embodiment, the permanent magnet material is an alloy comprising iron, platinum, and at least one material selected from copper, silver, magnesium, lead, zinc, bismuth, and antimony.Type: GrantFiled: June 18, 2003Date of Patent: April 25, 2006Assignee: Seagate Technology LLCInventors: Eric W. Singleton, David J. Larson, Christopher L. Platt, Kurt W. Wierman, James K. Howard
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Publication number: 20040048105Abstract: A thin film head comprising a GMR element formed of an antiferromagnetic layer, a pinning layer, a nonmagnetic conductive layer and a free magnetic layer; and a pair of the right and the left laminated longitudinal biasing layers, each of the layers containing a hard magnetic layer, a nonmagnetic layer and a soft magnetic layer provided on said free magnetic layer of GMR element. Said hard magnetic layer and said soft magnetic layer are antiferromagnetically exchange-coupled via said nonmagnetic layer, and said hard magnetic layer and said free magnetic layer locating next to said hard magnetic layer are ferromagnetically coupled. The present invention contains also a method for manufacturing the thin film head.Type: ApplicationFiled: August 13, 2003Publication date: March 11, 2004Inventors: Masaya Sakaguchi, Toshio Fukazawa
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Publication number: 20040047089Abstract: A transducing head includes a first bias element, a second bias element, and a magnetoresistive sensor positioned between the first bias element and the second bias element. The first bias element and the second bias element are each formed of a permanent magnet material having a remanent magnetic moment in a range of about 200 to about 800 emu/cm3. In a preferred embodiment, the permanent magnet material is an alloy comprising iron, platinum, and at least one material selected from copper, silver, magnesium, lead, zinc, bismuth, and antimony.Type: ApplicationFiled: June 18, 2003Publication date: March 11, 2004Applicant: Seagate Technology LLCInventors: Eric W. Singleton, David J. Larson, Christopher L. Platt, Kurt W. Wierman, James K. Howard
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Patent number: 6665156Abstract: By constituting a MR head with a pair of magnet films defining a recess on a lower gap layer, the recess having generally an inverted trapezoid shape in cross section; a magnetoresistive film covering a bottom and side wall of the recess and partial upper surfaces of the pair of magnet films; and a pair of electrically conductive films formed on the magnet films and being in contact with said magnetoresistive film only at a position outside of the recess, it becomes possible to reduce a variation in reading track widths of MR heads even under mass production.Type: GrantFiled: March 27, 2001Date of Patent: December 16, 2003Assignee: Yamaha CorporationInventors: Kenichi Miyazawa, Shuichi Sawada, Yukio Wakui
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Publication number: 20030214765Abstract: A transducing head has a magnetoresistive sensor, a first bias element, and a second bias element. The magnetoresistive sensor is positioned between the first and second bias elements, and has a sensor width. The first bias element has a first length and the second bias element has a second length. The direction of the first and second lengths are substantially similar to the direction of the sensor width. The first and second lengths in the range of about one-tenth to about twenty times the sensor width.Type: ApplicationFiled: January 21, 2003Publication date: November 20, 2003Applicant: Seagate Technology, LLCInventors: Mai Abdelhamid Ghaly, David James Larson, Paul Edward Anderson, Kristin J. Duxstad, Brenda Anne Everitt, Patrick John Moran, Steven Barclay Slade, Eric Walter Singleton
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Patent number: 6633466Abstract: A thin film head includes a GMR element formed of an antiferromagnetic layer, a pinning layer, a nonmagnetic conductive layer, a free magnetic layer, and a pair of the right and the left laminated longitudinal biasing layers. Each of the biasing layers contains a high coercivity ferromagnetic layer, a nonmagnetic layer and a low coercivity ferromagnetic layer provided on the free magnetic layer of the GMR element. The high coercivity ferromagnetic layer and low coercivity ferromagnetic layer are antiferromagnetically exchange-coupled via the nonmagnetic layer, and the high coercivity ferromagnetic layer and free magnetic layer located next to the high coercivity ferromagnetic layer are ferromagnetically coupled.Type: GrantFiled: December 14, 2000Date of Patent: October 14, 2003Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Masaya Sakaguci, Toshio Fukazawa
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Patent number: 6525912Abstract: A thin-film magnetic head includes a nonmagnetic lower gap layer, a nonmagnetic upper gap layer, a magnetoresistive layer, an electrode layer, and an intermediate gap layer. The magnetoresistive layer and the electrode layer are formed between the lower gap layer and the upper gap layer. The intermediate gap layer is disposed between the lower gap layer and the upper gap layer, and is formed in the region at both sides of the magnetoresistive layer in the track width direction and/or in the region behind the magnetoresistive layer in the depth direction. The length of the magnetoresistive layer in the depth direction is first determined, the width of the magnetoresistive layer in the track width direction is determined, and then the hard magnetic bias layers and the electrode layers are formed.Type: GrantFiled: December 8, 1998Date of Patent: February 25, 2003Assignee: Alps Electric Co., Ltd.Inventor: Kiyoshi Sato
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Publication number: 20030030949Abstract: A transducing head has a magnetoresistive sensor and first and second permanent magnet bias elements for providing longitudinal bias to the magnetoresistive sensor. The first and second permanent magnet bias elements are arranged on opposite sides of the magnetoresistive sensor and recessed a distance away from the magnetoresistive sensor. The transducing head of the present invention achieves increased read sensitivity by recessing the first and second permanent magnet bias elements away from the magnetoresistive sensor.Type: ApplicationFiled: December 20, 2001Publication date: February 13, 2003Inventors: Mai A. Ghaly, Steven B. Slade, Kristin J. Duxstad, David J. Larson, Eric W. Singleton
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Patent number: 6487056Abstract: The present invention provides an improved bias magnet-to-magnetoresistive element interface and method of fabrication. In a preferred embodiment, the wall/walls of an MR element opposing a bias layer are formed by over etching to provide vertical side walls without taper. In the preferred embodiment, a protective element is formed over the MR element to protect it during etch processes. In some embodiments, a filler layer is deposited prior to bias layer formation. In CIP embodiments, any portion of the filler layer forming on vertical side walls of the MR element is etched to provide an exposed side wall surface for contiguous bias layer formation. In CPP embodiments, the filler layer forms on a vertical back wall and electrically insulates the MR element from the bias layer.Type: GrantFiled: May 20, 2002Date of Patent: November 26, 2002Assignee: Read-Rite CorporationInventors: Matthew Gibbons, Kenneth E. Knapp, Ronald A. Barr, Benjamin P. Law, James Spallas, Ming Zhao
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Patent number: 6477020Abstract: A magneto-resistive head includes a stabilizing bias layer which applies a magnetization stabilizing bias field on a magneto-resistive layer of a magneto-resistive element, and a ferromagnetic underlayer which forms an underlayer with respect to the stabilizing bias layer. The ferromagnetic underlayer is made of Fe and has a film thickness in a range of 1.3 to 2.5 nm.Type: GrantFiled: November 10, 1999Date of Patent: November 5, 2002Assignee: Fujitsu LimitedInventors: Kenichi Aoshima, Hitoshi Kanai
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Patent number: 6462920Abstract: A system and method for providing a magnetoresistive head is disclosed. The method and system include providing a first gap and providing a seed layer. The seed layer is disposed above the first gap and has a space therein. The method and system further include providing a magnetoresistive element substantially covering the space in the seed layer and providing a hard bias layer above the seed layer. A portion of the hard bias layer is immediately adjacent to a portion of the magnetoresistive element.Type: GrantFiled: December 23, 1998Date of Patent: October 8, 2002Assignee: Read-Rite CorporationInventor: Rahmat Karimi
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Patent number: 6447689Abstract: An improved process for manufacturing a spin valve structure that has buried leads is disclosed. A key feature is the inclusion in the process of a temporary protective layer over the seed layer on which the spin valve structure will be grown. This protective layer is in place at the time that photoresist (used to define the location of the spin valve relative to the buried leads and longitudinal bias layers) is removed. The protective layer is later removed as a natural byproduct of surface cleanup just prior to the formation of the spin valve itself.Type: GrantFiled: June 5, 2000Date of Patent: September 10, 2002Assignee: Headway Technologies, Inc.Inventors: Chyu-Jiuh Torng, Chen-Jung Chien, Kochan Ju, Jei-Wei Chang
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Patent number: 6449135Abstract: The present invention is a magnetoresistive (MR) sensor (100) that combines the advantages of abutted junction structure and regular overlaid structure. The abutted junction design is used with the soft adjacent layer (SAL) (108) and the overlaid structure is used with the MR element (120). The method of making the MR sensor (100) comprises depositing SAL (108) on top of the gap layer (106) and depositing spacer material (110) on top of the SAL (108). A mask (130) is placed over the central region of the spacer material (110) and SAL (108). The spacer material (110) and SAL (108) are removed in the areas not covered by the mask (130). An underlayer material (112) is deposited in the areas where the SAL (108) and spacer material (110) were removed. A hard-biasing material (114) is deposited on top of the underlayer (112).Type: GrantFiled: November 6, 1998Date of Patent: September 10, 2002Assignee: Seagate Technology LLCInventors: Juren Ding, Song Sheng Xue, Juan Fernandez-deCastro, James Dolejsi, Patrick Joseph Ryan
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Patent number: 6421212Abstract: The present invention provides an improved bias magnet-to-magnetoresistive element interface and method of fabrication. In a preferred embodiment, the wall/walls of an MR element opposing a bias layer are formed by over etching to provide vertical side walls without taper. In the preferred embodiment, a protective element is formed over the MR element to protect it during etch processes. In some embodiments, a filler layer is deposited prior to bias layer formation. In CIP embodiments, any portion of the filler layer forming on vertical side walls of the MR element is etched to provide an exposed side wall surface for contiguous bias layer formation. In CPP embodiments, the filler layer forms on a vertical back wall and electrically insulates the MR element from the bias layer.Type: GrantFiled: September 21, 1999Date of Patent: July 16, 2002Assignee: Read-Rite CorporationInventors: Matthew Gibbons, Kenneth E. Knapp, Ronald A. Barr, Benjamin P. Law, James Spallas, Ming Zhao
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Patent number: 6385017Abstract: A spin valve device comprises a free layer, a spacer layer, a pinned layer, an antiferromagnetic layer, and a patterned underlayer that includes a magnetic material for providing trackwidth and longitudinal bias. The patterned underlayer can comprise a buffer layer, an antiferromagnetic layer and a ferromagnetic layer. Alternatively, the patterned underlayer can comprises a buffer layer, a chromium layer and a hard biasing, permanent magnetic layer which provides trackwidth and longitudinal bias. A lower conductor can be located on the underlayer.Type: GrantFiled: September 30, 1999Date of Patent: May 7, 2002Assignee: Headway Technologies, Inc.Inventors: Tai Min, Po-Kang Wang, Moris Musa Dover
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Patent number: 6351357Abstract: A magneto-resistive sensor has a magneto-resistive element with an active area with an electrical resistance sensitive to changes in magnetic flux. Two hard magnets on opposing sides of the magneto-resistive element magnetically bias the magneto-resistive element. Each hard magnet includes a seed layer of a soft magnetic, electrically conductive material between two magnet layers of a hard magnetic, electrically conductive material laminated longitudinally together such that the seed layer and the magnet layers exhibit unified magnetic properties. The seed layer is preferably an amorphous material such as nitrided sendust. The laminated structure allows for a thicker magnet structure with low electrical resistance but without degradation of magnetic properties due to the increased thickness.Type: GrantFiled: September 20, 2000Date of Patent: February 26, 2002Assignee: Seagate Technology LLCInventors: Song Sheng Xue, James F. Dolejsi, Patrick J. Ryan
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Publication number: 20010026425Abstract: By constituting a MR head with a pair of magnet films defining a recess on a lower gap layer, the recess having generally an inverted trapezoid shape in cross section; a magnetoresistive film covering a bottom and side wall of the recess and partial upper surfaces of the pair of magnet films; and a pair of electrically conductive films formed on the magnet films and being in contact with said magnetoresistive film only at a position outside of the recess, it becomes possible to reduce a variation in reading track widths of MR heads even under mass production.Type: ApplicationFiled: March 27, 2001Publication date: October 4, 2001Applicant: Yamaha CorporationInventors: Kenichi Miyazawa, Shuichi Sawada, Yukio Wakui
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Publication number: 20010021089Abstract: The first ferromagnetic layer is made to show a single magnetic domain to prevent any magnetic wall from appearing. A pair of bias layers 4, 4 made of a hard magnetic material showing a high resistivity are arranged at opposite ends of a TMR thin film 3. As a result, the sense current flowing through the TMR thin film 3 is prevented from diverting to the bias layers 4, 4. Thus, a sufficiently strong bias magnetic field can be applied to the TMR thin film 3. As a result, the free layer 13 of the TMR thin film 3 is made to show a single magnetic domain to prevent any magnetic wall from appearing.Type: ApplicationFiled: February 28, 2001Publication date: September 13, 2001Applicant: Sony CorporationInventors: Teiichi Miyauchi, Hiroshi Kano, Tetsuya Mizuguchi, Minoru Ikarashi
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Patent number: 6278595Abstract: The present invention is a magnetoresistive (MR) sensor that combines a hard-biasing material with an underlayer of cubic-titanium-tungsten to improve the stability of the MR sensor. The permanency of the hard-biasing material affects both the transverse and longitudinal biasing of the MR sensor, which in turn affects the stability of the MR sensor. The stability of the hard-biasing material is improved by combining it with an underlayer of cubic-titanium-tungsten. The underlayer enhances the hard-biasing material by improving the longitudinal magnetic anisotropy, the coercivity, and the in-plane squareness of the hard-biasing material. The combination of hard-biasing material and cubic-titanium-tungsten underlayer can be used in a variety of MR sensor embodiments, specifically an abutted junction or an overlaid structure. The method of making the abutted junction or overlaid structures is also improved by using cubic-titanium-tungsten as the underlayer of the hard-biasing material.Type: GrantFiled: January 26, 1999Date of Patent: August 21, 2001Assignee: Seagate Technology LLCInventors: Song Sheng Xue, Bogdan Marius Simion, James Frank Dolejsi, Patrick Joseph Ryan