Patents by Inventor Mohammad Mirzamaani
Mohammad Mirzamaani has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7879467Abstract: Improvements to magnetic recording device including magnetic recording media are described. The improvements include the addition of copper to the recording layer as well as improved underlayers. In addition, improved manufacturing processes and magnetic/recording properties for media through heating and oxidation are described.Type: GrantFiled: December 14, 2009Date of Patent: February 1, 2011Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Jack Chang, Mohammad Mirzamaani, Kai Tang
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Publication number: 20100104893Abstract: Improvements to magnetic recording device including magnetic recording media are described. The improvements include the addition of copper to the recording layer as well as improved underlayers. In addition, improved manufacturing processes and magnetic/recording properties for media through heating and oxidation are described.Type: ApplicationFiled: December 14, 2009Publication date: April 29, 2010Inventors: Jack Chang, Mohammad Mirzamaani, Kai Tang
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Patent number: 7670694Abstract: Improvements to magnetic recording device including magnetic recording media are described. The improvements include the addition of copper to the recording layer as well as improved underlayers. In addition, improved manufacturing processes and magnetic/recording properties for media through heating and oxidation are described.Type: GrantFiled: December 22, 2006Date of Patent: March 2, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Jack Chang, Mohammad Mirzamaani, Kai Tang
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Patent number: 7514161Abstract: A laminated film structure is disclosed comprising multiple ferromagnetic layers achieving improved data recording performance. A non-magnetic spacer layer is disposed between an upper ferromagnetic layer and an antiferromagnetic coupled (AFC) structure. The AFC structure is comprised of a ferromagnetic layer and an antiferromagnetic slave layer. The ferromagnetic layer in the AFC structure, referred to as lower ferromagnetic layer, may contain tantalum to promote chromium segregation at the grain boundaries to achieve magnetic decoupling of the grains with relatively thin boundaries, improving medium signal-to-noise ratio while maintaining good thermal stability of the medium. In some embodiments, the interlayer is a five-element alloy such as a CoCrPtBTa alloy.Type: GrantFiled: February 15, 2005Date of Patent: April 7, 2009Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Mary Frances Minardi, Mohammad Mirzamaani, Kai Tang
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Patent number: 7419730Abstract: An antiferromagnetically coupled (AFC) magnetic recording medium with an AFC master layer comprising at least two magnetic layers with the top magnetic layer including copper is described. The slave layer is separated from the master layer structure by a nonmagnetic spacer layer selected to antiferromagnetically couple the layers. The master layer structure according to the invention includes a bottom and top layer of distinct ferromagnetic materials. Preferably, the top layer of the master layer is a cobalt alloy including from 1 to 5 at. % copper with an example being CoPt13Cr20B8Cu2. The AFC magnetic layer structure can be used with a variety of substrates including circumferentially textured glass and NiP/AlMg.Type: GrantFiled: August 31, 2004Date of Patent: September 2, 2008Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Xiaoping Bian, Mary Frances Doerner, Tetsuya Kanbe, Mark Mercado, Mohammad Mirzamaani, Adam Polcyn, Kai Tang
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Publication number: 20080152955Abstract: Improvements to magnetic recording device including magnetic recording media are described. The improvements include the addition of copper to the recording layer as well as improved underlayers. In addition, improved manufacturing processes and magnetic/recording properties for media through heating and oxidation are described.Type: ApplicationFiled: December 22, 2006Publication date: June 26, 2008Inventors: Jack Chang, Mohammad Mirzamaani, Kai Tang
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Publication number: 20070292721Abstract: A perpendicular magnetic recording medium including improvements to the recording layer (RL), exchange break layer (EBL), soft underlayer (SUL), overcoat (OC), adhesion layer (AL) and the combination of the layers. Advances in the RL include a cap layer. Improvements in the EBL include a multiple layer EBL.Type: ApplicationFiled: April 25, 2007Publication date: December 20, 2007Inventors: Andreas Berger, Xiaoping Bian, Qing Dai, Hoa Do, Eric Fullerton, Bernd Heinz, Yoshihiro Ikeda, David Margulies, Mary Minardi, Mohammad Mirzamaani, Hal Rosen, Natacha Supper, Kentaro Takano, Min Xiao
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Patent number: 7300713Abstract: A thin film disk for use in magnetic recording with an underlayer structure that includes a layer of CrMoZr, CrMoNb or CrMoMn is described. The preferred embodiment includes a circumferentially textured glass substrate, a pre-seed layer, a B2 seed layer, an underlayer structure and a magnetic layer stack with a plurality of layers. The preferred underlayer structure has a first underlayer of CrTi followed by a second underlayer of CrMoZr. The preferred B2 seed layer material is RuAl. The preferred pre-seed layer is CrTiAl. The preferred magnetic layer stack is CoCr/CoPtCrB/CoPtCrBCu. The preferred embodiment is useful for longitudinal magnetic recording. The in-plane crystallographic orientation, the Mrt orientation ratio and the media SNR are improved by the inclusion of the CrMoZr, CrMoNb or CrMoMn according to the invention.Type: GrantFiled: October 29, 2004Date of Patent: November 27, 2007Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Xiaoping Bian, Jack Chang, Ernesto E. Marinero, Mohammad Mirzamaani
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Publication number: 20070037015Abstract: A laminated magnetic recording medium comprising two magnetic layers that are substantially decoupled. The upper magnetic layer is preferably a cobalt alloy that includes tantalum. The tantalum in the upper magnetic layer provides the advantage of improving media SNR with good media stability.Type: ApplicationFiled: August 10, 2005Publication date: February 15, 2007Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Mohammad Mirzamaani, Kai Tang
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Publication number: 20070019328Abstract: An embodiment of the invention is a laminated magnetic recording medium comprising two magnetic layers that are substantially decoupled. The lower magnetic layer comprises two sublayers. The upper magnetic sublayer is preferably a cobalt alloy having lower chromium and higher boron content than the lower magnetic sublayer. The upper sublayer composition is selected to have higher coercivity (Hc), narrower PW50 and higher resolution. The lower sublayer composition is selected for higher SNR, thermal stability and better overwrite. The laminated structure can also be used in an embodiment which has a slave magnetic layer separated from the lower magnetic layer by an AFC spacer.Type: ApplicationFiled: July 25, 2005Publication date: January 25, 2007Inventors: Mohammad Mirzamaani, Kai Tang
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Publication number: 20060183003Abstract: A laminated film structure is disclosed comprising multiple ferromagnetic layers achieving improved data recording performance. A non-magnetic spacer layer is disposed between an upper ferromagnetic layer and an antiferromagnetic coupled (AFC) structure. The AFC structure is comprised of a ferromagnetic layer and an antiferromagnetic slave layer. The ferromagnetic layer in the AFC structure, referred to as lower ferromagnetic layer, may contain tantalum to promote chromium segregation at the grain boundaries to achieve magnetic decoupling of the grains with relatively thin boundaries, improving medium signal-to-noise ratio while maintaining good thermal stability of the medium. In some embodiments, the interlayer is a five-element alloy such as a CoCrPtBTa alloy.Type: ApplicationFiled: February 15, 2005Publication date: August 17, 2006Inventors: Mary Minardi, Mohammad Mirzamaani, Kai Tang
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Publication number: 20060093866Abstract: A thin film disk for use in magnetic recording with an underlayer structure that includes a layer of CrMoZr, CrMoNb or CrMoMn is described. The preferred embodiment includes a circumferentially textured glass substrate, a pre-seed layer, a B2 seed layer, an underlayer structure and a magnetic layer stack with a plurality of layers. The preferred underlayer structure has a first underlayer of CrTi followed by a second underlayer of CrMoZr. The preferred B2 seed layer material is RuAl. The preferred pre-seed layer is CrTiAl. The preferred magnetic layer stack is CoCr/CoPtCrB/CoPtCrBCu. The preferred embodiment is useful for longitudinal magnetic recording. The in-plane crystallographic orientation, the Mrt orientation ratio and the media SNR are improved by the inclusion of the CrMoZr, CrMoNb or CrMoMn according to the invention.Type: ApplicationFiled: October 29, 2004Publication date: May 4, 2006Inventors: Xiaoping Bian, Jack Chang, Ernesto Marinero, Mohammad Mirzamaani
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Publication number: 20060046102Abstract: An antiferromagnetically coupled (AFC) magnetic recording medium with an AFC master layer comprising at least two magnetic layers with the top magnetic layer including copper is described. The slave layer is separated from the master layer structure by a nonmagnetic spacer layer selected to antiferromagnetically couple the layers. The master layer structure according to the invention includes a bottom and top layer of distinct ferromagnetic materials. Preferably, the top layer of the master layer is a cobalt alloy including from 1 to 5 at. % copper with an example being CoPt13Cr20B8Cu2. The AFC magnetic layer structure can be used with a variety of substrates including circumferentially textured glass and NiP/AlMg.Type: ApplicationFiled: August 31, 2004Publication date: March 2, 2006Inventors: Xiaoping Bian, Mary Doerner, Tetsuya Kanbe, Mark Mercado, Mohammad Mirzamaani, Adam Polcyn, Kai Tang
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Publication number: 20050048328Abstract: A thin film magnetic media structure with a bi-layer structure of amorphous chromium titanium (CrTi) followed by an amorphous layer of nickel phosphorus (NiP) is disclosed. After the NiP has been deposited it is exposed to oxygen to form an oxidized surface. Preferably the underlayer is deposited directly onto the oxidized NiP surface. The bi-layer structure of CrTi/NiP promotes excellent in-plane crystallographic orientation in the cobalt alloy magnetic layer(s) and allows: an ultra-thin chromium underlayer to be used which provides better control over grain size and distribution. When the CrTi/NiP bi-layer structure is combined with a circumferentially textured substrate, preferably glass, a high Mrt orientation ratio (OR) results.Type: ApplicationFiled: August 29, 2003Publication date: March 3, 2005Inventors: Xiaoping Bian, Mary Doerner, Mohammad Mirzamaani, Adam Polcyn, Qi-Fan Xiao
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Publication number: 20050031909Abstract: The applicants disclose a thin film magnetic media structure with a pre-seed layer of CrTi. The CrTi pre-seed layer presents an amorphous or nanocrystalline structure. The preferred seed layer is RuAl for use with the CrTi pre-seed layer. The use of the CrTi/RuAl bilayer structure provides superior adhesion to the substrate and resistance to scratching, as well as, excellent coercivity and signal-to-noise ratio (SNR) and reduced cost over the prior art. One embodiment of the invention sputter-deposits a CrTi pre-seed layer and a RuAl seed layer followed by an underlayer and at least one magnetic layer on a circumferentially polished substrate structure to achieve an Mrt orientation ratio greater than one. Two methods according to the invention allow the Mrt orientation ratio of the disk to be adjusted or maximized by varying the thickness of the RuAl seed layer and/or altering the atomic percentage of titanium in the pre-seed layer.Type: ApplicationFiled: July 29, 2004Publication date: February 10, 2005Inventors: Xiaoping Bian, Mary Doerner, James Hagan, Tim Minvielle, Mohammad Mirzamaani, Adam Polcyn, Kai Tang
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Patent number: 6174582Abstract: A method of fabricating a thin film magnetic disk including depositing a seed layer of a refractory metal such as tantalum, Cr, Nb, W, V, or Mo and a reactive element such as N or O; depositing a nonmagnetic underlayer onto the seed layer; and depositing a magnetic layer is disclosed. Also disclosed is a thin film magnetic disk having a substrate; a seed layer comprising tantalum and at least about 1 atomic-% of nitrogen or oxygen; an underlayer comprising Cr or an alloy of chromium deposited onto the seed layer, the underlayer preferably having a preferred orientation of [200]; and a magnetic layer deposited onto the underlayer, the magnetic layer preferably having a preferred orientation of [11{overscore (2)}0]. Also disclosed is a disk drive using the thin film magnetic disk of the invention.Type: GrantFiled: February 6, 1998Date of Patent: January 16, 2001Assignee: International Business Machines CorporationInventors: Xiaoping Bian, Shanlin Duan, Jinshan Li, Mohammad Mirzamaani