Hostname: page-component-76fb5796d-vvkck Total loading time: 0 Render date: 2024-04-27T22:14:18.147Z Has data issue: false hasContentIssue false
  • English
  • Français

Correlation of Structure and Properties in Thin-Film Magnetic Media

Published online by Cambridge University Press:  15 February 2011

T. P. Nolan ,
R. Sinclair ,
R. Ranjan ,
T. Yamashita ,
G. Tarnopolsky  and
W. Bennett
T. P. Nolan
Affiliation:
Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305
R. Sinclair
Affiliation:
Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305
R. Ranjan
Affiliation:
Komag Inc. 591 Yosemite Drive, Milpitas, CA 95035
T. Yamashita
Affiliation:
Komag Inc. 591 Yosemite Drive, Milpitas, CA 95035
G. Tarnopolsky
Affiliation:
Komag Inc. 591 Yosemite Drive, Milpitas, CA 95035
W. Bennett
Affiliation:
Komag Inc. 591 Yosemite Drive, Milpitas, CA 95035
Get access

Abstract

Correlation of detailed microstructural information obtained from a temperature series (25–275°C) of otherwise identical CoCrTa/Cr recording media with detailed recording performance measurements demonstrates two mechanisms for magnetic isolation.

Media were prepared by sputter deposition of 75 nm Cr underlayers and 60 nm Co84Cr12Ta4 layers onto circumferentially textured NiP plated aluminum substrates using an Intevac MDP-250 machine.

High-resolution transmission electron microscopy (HRTEM) and high-resolution scanning electron microscopy (HRSEM) show columnar isolation by voiding, via the mechanism of shadowing during low temperature growth. Shadowing decreases with increasing temperature until voiding disappears at 150°C. At high temperature (275°C), large intergranular separation is observed, which has been attributed to elemental segregation. This separation decreases as temperature decreases, until it disappears at 150°C.

Detailed magnetic recording measurements show that the maximum normalized media noise power is observed at 150°C. It decreases as more isolated structures are formed by increasing or decreasing temperature. Uniform magnetization noise, a measurement related to crosstrack correlation length within a magnetization transition also shows this trend.

It is suggested that HRTEM shows two different microstructural features that control magnetic correlation lengths and resulting media noise.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 343: Symposium H – Polycrystalline Thin Films - Structure, Texture, Properties and Applications , 1994 , 297
Copyright
Copyright © Materials Research Society 1994

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Zhu, J. G. and Bertram, H. N., J. Appl. Phys., 63, 3248 (1988).CrossRefGoogle Scholar
2. Chen, T., IEEE Trans. Magn., 17, 1181 (1981).CrossRefGoogle Scholar
3. Silva, T. J. and Bertram, H. N., IEEE Trans. Magn., 26, 3129 (1990).CrossRefGoogle Scholar
4. Tarnopolsky, G. J., Bertram, H. N. and Tran, L. T., J. Appl. Phys., 69, 4730 (1991).CrossRefGoogle Scholar
5. Nolan, T. P., Sinclair, R., Yamashita, T., and Ranjan, R., J. Appl. Phys., 73, 5117 (1993).CrossRefGoogle Scholar
6. Ranian, R., Bennett, W. R., Tarnopolsky, G. J., Yamashita, T., Nolan, T. P. and Sinclair, R., J. Appl. Phys., in press.Google Scholar
7. Bertero, G. A., Bertram, H. N. and Barnett, D. M., IEEE Trans. Magn. 29, 67 (1993)CrossRefGoogle Scholar
8. Maeda, Y. and Takei, K., IEEE Trans. Magn., 27, 4721 (1991).CrossRefGoogle Scholar
9. Lu, M., Chen, Q., Judy, J. H. and Sivertsen, J. M., submitted for publication.Google Scholar
10. Thornton, J. A., Ann. Rev. Mater. Sci., 7, 239 (1977).CrossRefGoogle Scholar
11. Nolan, T. P., Sinclair, R., Yamashita, T., and Ranjan, R., J. Appl. Phys., 73, 5566 (1993).CrossRefGoogle Scholar
12. Nolan, T. P., Sinclair, R., Yamashita, T., and Ranjan, R., IEEE Trans. Magn., 29, 292 (1993).CrossRefGoogle Scholar
13. Daval, J. and Randet, D., IEEE Trans. Magn. 6, 768 (1970).CrossRefGoogle Scholar
14. Cullity, B. D., Introduction to Magnetic Materials (Addison Wesley, Reading, 1972) Ch. 9Google Scholar