Seagate Technology Incorporated

Komag Corporation

Charles Changqing Chen

Gerardo Bertero

Tu Chen

Tsutomu Tom Yamashita

Abebe Hailu

Taesun Ernest Kim

Michinobu Suekane

Makoto Imakawa

Mariana Rodica Munteanu

Wei Cao

Shoutao Wang

Steve Kuo-Hsing Hwang

Thanh Thien Ha

Alan Huang

CoCrPtB is a conventional material used in some of the layers of a thin film magnetic media structure used for recording data in data storage devices such as hard drives. Typically the CoCrPtB layers used for magnetic media have high Cr and low B in bottom magnetic layers and low Cr and high B in top magnetic layers. In accordance with one embodiment of this invention and to improve media electrical performance, fifth elements, such as Ta, Nb and Hf, etc. were added to the CoCrPtB materials, resulting in CoCrPtB&#x2014;X, to enhance the grain segregation. The five element CoCrPtB&#x2014;X layers were deposited using a pulsed direct current sputter technique instead of conventional direct current sputtering techniques. The resulting magnetic media structure having CoCrPtB&#x2014;X alloy layers exhibits an increase in coercivity Hc and improvement in recording performance.

Magnetic recording media having five element alloy deposited using pulsed direct current sputtering

A magnetic recording medium having a substrate, underlayer, a low moment stabilizing layer, an antiferromagnetic coupling layer, a low magnetic layer having a magnetic saturation of equal to or less than 250 emu/cm, and a high moment magnetic layer having a magnetic saturation of more than 250 emu/cm, in this order, is disclosed. The magnetic recording medium has a weak coupling strength of Jex &#x2266;0.05.

Weak antiferromagnetically coupled media with a five element magnetic alloy and a low moment stabilizing layer

A thin film magnetic according medium with enhanced coercivity is provided. The magnetic recording medium comprises a non-magnetic substrate having a surface and a layer stack atop the substrate surface. The layer stack comprises a magnetic recording layer and a dual intermediate layer structure below the magnetic recording layer comprising a base layer and a non-magnetic layer between the base layer and the magnetic recording layer. The non-magnetic layer has a thickness less than that necessary for RKKY coupling between the base layer and the magnetic recording layer, and provides the medium with increased coercivity.

Thin-film magnetic recording media with dual intermediate layer structure for increased coercivity

A magnetic medium having at least two intermediate layers between an underlayer and a magnetic layer. The first intermediate layer is designed to provide a good lattice match to the underlayer, while the second intermediate layer is designed to provide a good lattice match to the magnetic layer. Typically, the underlayer has one structure, such as body centered cube, while the magnetic layer has a second structure such as hexagonal close pack. In preferred embodiments, the transition from the one structure to the other structure occurs in the intermediate layers. For example, the first intermediate layer may be a hexagonal close pack structure. Because of the mismatch between the underlayer and the first layer, there may be crystal defects in this first intermediate layer. However, any remaining stress and mismatch is absorbed through the second layer, so that the second layer presents a substantially defect-free surface on which the magnetic layer may grow. Because the second layer is closely matched to the magnetic layer, the magnetic layer continues to grow in a defect-free fashion. In other embodiments of the present invention, a spacer layer having a hexagonal close pack structure may be used between two or more portions of a magnetic layer.

Magnetic thin film recording media having extremely low noise and high thermal stability

In this invention, an ultra thin layer of CoCr alloy nucleation layer is sputtered at an extremely low deposition rate above a predominantly (200) oriented Cr film followed by a CoCrPt based alloy sputtered film at higher rates and moderate temperatures. This structure creates a media which has very high Hc, and excellent PW50, low noise and excellent low TNLD values. By using this technique, the CoCrPt magnetic film achieves excellent in-plane crystallographic orientation, and high Hc is achieved with minimal amount of Pt addition to the magnetic film. The method allows very fine grain structure of cobalt to be formed which contributes to good signal to noise ratio. A fine grain structure combined with chromium segregation between the grains improve the signal to noise ratio even more. A high degree of in-plane c-axis orientation is achieved in the cobalt layer which provides very high hysteresis loop squareness which helps to improve the OW and TNLD. The perfection of the grains is very high so that high anisotropy is obtained in the magnetic layer, resulting in high Hc without the necessity of addition of high level of Pt. The high degree of crystalline perfection also contributes to low TNLD.

Ultra-thin nucleation layer for magnetic thin film media and the method for manufacturing the same

Ultra-thin nucleation layer for magnetic thin film media and the method

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Milpitas, CA, United States of America

Charles Changqing Chen