David C Laughlin

US Patent:

6432563, Aug 13, 2002

Filed:

Apr 3, 2000

Appl. No.:

09/541245

Inventors:

Jie Zou - Pittsburgh PA
David N. Lambeth - Pittsburgh PA
David E. Laughlin - Pittsburgh PA

Assignee:

Carnegie Mellon University - Pittsburgh PA

International Classification:

G11B 566

US Classification:

428694TS, 428694 T, 428694 TM, 428900

Abstract:

The present invention provides a magnetic recording media incorporating Zn containing layers in close proximity to a magnetic layer to provide media having increased coercivity and lower noise. The Zn containing layer can be incorporated in a rotating, translating or stationary recording media to operate in conjunction with magnetic transducing heads for recording and reading of magnetic data, as well as other applications. The magnetic recording medium of the invention preferably includes a Co or Co alloy film magnetic layer, underlayer structures to promote epitaxial crystalline structure in the magnetic layer, and a Zn containing layer to promote isolation between the magnetic grains. The medium can further include seed layers, underlayers, intermediate layers, and overlayers. The process of manufacture includes promoting diffusion of Zn to the magnetic layer grain boundaries.

US Patent:

6596417, Jul 22, 2003

Filed:

Sep 29, 2000

Appl. No.:

09/677557

Inventors:

Yu-Nu Hsu - Pittsburgh PA
David E. Laughlin - Pittsburgh PA
David N. Lambeth - Pittsburgh PA

Assignee:

Carnegie Mellon University - Pittsburgh PA

International Classification:

G11B 566

US Classification:

428694TS, 428611, 428900, 427131, 20419215, 2041922

Abstract:

The present invention provides a longitudinal magnetic recording media having a substrate, a Co or Co alloy based magnetic layer arid an underlayer disposed between the substrate and the magnetic layer. The underlayer is made of a material having a Ga Pt crystalline structure, most preferably Ni Al. Several intermediate layers, disposed between the underlayer and the magnetic layer may also be included.

US Patent:

6849349, Feb 1, 2005

Filed:

Oct 21, 2002

Appl. No.:

10/274768

Inventors:

Timothy John Klemmer - Pittsburgh PA, US
Ganping Ju - Wexford PA, US
René Johannes Marinus van de Veerdonk - Pittsburgh PA, US
Todd Dennis Leonhardt - Pittsburgh PA, US
David Eugene Laughlin - Pittsburgh PA, US

Assignee:

Carnegie Mellon University - Pittsburgh PA

International Classification:

G11B 566
G11B 570
H01J 100

US Classification:

428694T, 428611, 428900

Abstract:

Magnetic films having magnetic regions and non-magnetic regions are disclosed. The film is subjected to ion irradiation in order to produce chemically disordered regions in the film. The irradiated disordered regions may correspond to the non-magnetic regions of the film. Alternatively, the irradiated disordered regions may correspond to the magnetic regions of the film. In one embodiment, portions of a magnetic CrPtfilm are converted to non-magnetic regions by irradiating the regions with boron ions which disorder the CrPtfilm in the treated regions. The film may be patterned into magnetic regions and non-magnetic regions for applications such as magnetic recording media in computer disc drive systems.

US Patent:

8211557, Jul 3, 2012

Filed:

Jan 31, 2007

Appl. No.:

11/700308

Inventors:

Jian-Gang Zhu - Pittsburgh PA, US
David E. Laughlin - Pittsburgh PA, US

Assignee:

Carnegie Mellon University - Pittsburgh PA

International Classification:

G11B 5/66

US Classification:

4288281, 360 59, 360135, 427128, 369 131

Abstract:

A magnetic microstructure comprising (i) a magnetic storage layer having a magnetic easy axis perpendicular to a film plane of the storage magnetic layer; (ii) a magnetic assist layer having a magnetic easy axis in the film plane; and (iii) a phase transition interlayer between the magnetic storage layer and the magnetic assist layer. The phase transition layer comprises a material, such as FeRh, that switches from antiferromagnetic at ambient to ferromagnetic at a transition temperature that is greater than ambient, but below the Curie temperature. When the phase transition interlayer is in antiferromagnetic phase, there exists little magnetic coupling between the storage and assist layers. When the interlayer changes to ferromagnetic phase, the interlayer couples the magnetic moments of the storage and assist layer ferromagnetically. If the anisotropy field-thickness product of the two layers is similar and the coupling is sufficiently strong, the effective magnetic anisotropy of the storage layer and the assist layer essentially vanishes.

US Patent:

8449730, May 28, 2013

Filed:

Jul 20, 2009

Appl. No.:

12/505921

Inventors:

En Yang - Pittsburgh PA, US
David E. Laughlin - Pittsburgh PA, US
Jian-Gang Zhu - Pittsburgh PA, US

Assignee:

Carnegie Mellon University - Pittsburgh PA

International Classification:

C23C 14/00
C23C 14/32

US Classification:

2041921, 20419215, 427130

Abstract:

A process of fabricating a perpendicular magnetic recording medium. In one embodiment, the process may comprise forming a metallic buffer layer with a (002) texture on an underlayer using a deposition process performed at a temperature below 30 C. The underlayer may have a crystalline (001) texture. The process may further comprise forming a perpendicular magnetic recording layer on top of the metallic buffer layer using a deposition process performed at a temperature above 350 C. The magnetic recording layer may comprise a magnetic material with a L1crystalline structure and with a c-axis perpendicular to a plane of the perpendicular magnetic recording layer. The process may further comprise removing metal of the metallic buffer layer from a top surface of the perpendicular magnetic recording layer that moved to the top surface of the perpendicular magnetic recording layer during the forming of the perpendicular magnetic recording layer.

US Patent:

20100265028, Oct 21, 2010

Filed:

Feb 21, 2007

Appl. No.:

12/310595

Inventors:

Michael E. McHenry - Pittsburgh PA, US
Jianguo Long - San Jose CA, US
Vladimir Keylin - Pittsburgh PA, US
David Laughlin - Pittsburgh PA, US
Joseph Huth - Butler PA, US
Edward Conley - North Huntingdon PA, US

Assignee:

CARNEGIE MELLON UNIVESITY - Pittsburgh PA

International Classification:

H01F 17/04
H01F 1/01
C22C 38/16
C22C 30/02
C21D 6/00
C22F 1/00
H01F 27/24

US Classification:

336221, 148304, 420 89, 420582, 148621, 148707, 148538, 148540, 148567, 336233

Abstract:

The invention discloses a soft magnetic amorphous alloy and a soft magnetic nanocomposite alloy formed from the amorphous alloy. Both alloys comprise a composition expressed by the following formula: (FeCoM)TBNwhere, M is at least one element selected from the group consisting of Ni and Mn; T is at least one element selected from the group consisting of Nb, W, Ta, Zr, Hf, Ti, Cr, Cu, Mo, V and combinations thereof, and the content of Cu when present is less than or equal to 2 atomic %; N is at least one element selected from the group consisting of Si, Ge, C, P and Al; and 0.01≦x+y

US Patent:

20120281512, Nov 8, 2012

Filed:

May 29, 2012

Appl. No.:

13/482078

Inventors:

Jian-Gang Zhu - Pittsburgh PA, US
David E. Laughlin - Pittsburgh PA, US

Assignee:

Carnegie Mellon University - Pittsburgh PA

International Classification:

G11B 13/04

US Classification:

369 1324, G9B 13003

Abstract:

A method of writing binary data comprising (i) heating a magnetic microstructure from an initial temperature to an above-ambient temperature that is not less than a transition temperature for the magnetic microstructure, which causes a phase transition interlayer of the magnetic microstructure to transition from an antiferromagnetic phase to a ferromagnetic phase; and (ii) reversing an orientation of magnetization of a magnetic storage layer of the magnetic microstructure with a magnetic field while the phase transition interlayer is in the ferromagnetic phase.

US Patent:

62484168, Jun 19, 2001

Filed:

Nov 10, 1997

Appl. No.:

8/967669

Inventors:

David N. Lambeth - Pittsburgh PA
David E. Laughlin - Pittsburgh PA
Wei Yang - Pittsburgh PA
Heng Gong - Pittsburgh PA
Jie Ziou - Pittsburgh PA

Assignee:

Carnegie Mellon University - Pittsburgh PA

International Classification:

G11B 566

US Classification:

428 653

Abstract:

The present invention provides for magnetic and magneto-optic recording media, transducers and data storage devices constructed therefrom that have highly oriented films having long range order in the crystal structure of the film. The recording medium includes a magnetic recording layer comprised of Co-based material, such as Co or one or more Co alloys having a (1010) crystal texture, a substrate, a first underlayer having a fcc structure and a (110) crystal texture disposed between the substrate and the magnetic recording layer. A second underlayer having a bcc structure and a (112) crystal texture is also disposed between the magnetic recording layer and the first underlayer. In particular, if a (110) Si single crystal substrate is non-oxidized certain metals having fcc structures, such as Ag, Cu, Al, and Au and fcc derivative structures, such L1. sub. 0 and L1. sub. 2 structures, can be epitaxially grown on the Si surface. While the one unit cell to one unit cell lattice match between fcc Ag and A4 (diamond) Si is quite poor, multiples of the Ag unit cell distance fit very well on the Si surface.