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L10 Ordered Intermetallics for Ultrahigh Density Magnetic Recording Media: Phase Formation and the Role of Alloy Chemistry and Composition

Published online by Cambridge University Press:  26 February 2011

David C. Berry  and
Katayun Barmak
David C. Berry
Affiliation:
[email protected] Mellon UniversityDept. of Materials Science and EngineeringPittsburgh PA 15213United States
Katayun Barmak
Affiliation:
[email protected], Carnegie Mellon University, Dept. of Materials Science and Engineering, Pittsburgh, PA, 15213, United States
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Abstract

In this paper we provide a summary review of our research regarding the effect of composition on the A1 to L10 transformation in binary FePt with compositions in the range of 39.3 to 55.3 at.% Pt and ternary FeCuPt alloys with Cu additions in the range of 1.0 to 19.4 at.%. These binary and ternary alloy films have been studied using non-isothermal differential scanning calorimetry (DSC) combined with the calculation of TTT diagrams generated via experimentally validated Johnson-Mehl-Avrami-Kolmogorov (JMAK) analysis. Composition is found to play a significant role in the transformation kinetics in both FePt and FeCuPt. However, when comparing equivalent FePt and FeCuPt alloys, the addition of Cu has no significant effect. TTT diagrams show that as little as a 90 °C increase in peak temperature from the DSC measurements can result in a >300× increase in the time required for full transformation using isothermal anneals. Our results on the effect of Cu additions are compared with those reported in the literature.

Keywords

phase transformationcalorimetrythin film
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 980: Symposium II – Advanced Intermetallic-Based Alloys , 2006 , 0980-II03-05
Copyright
Copyright © Materials Research Society 2007

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References

1. Murdock, E. S., Simmons, R. F., and Davidson, R., IEEE Trans. Mag. 28, 3078 (1992).10.1109/20.179719Google Scholar
2. Toney, M. F., Lee, W. Y., Hedstrom, J. A., and Kellock, A., J. Appl. Phys. 93, 9902 (2003).10.1063/1.1577226Google Scholar
3. Aboaf, J. A., McGuire, T. R., Herd, S. R., and Klokholm, E., IEEE Trans. Mag. 20, 1642 (1984).Google Scholar
4. Coffey, K. R., Parker, M. A., and Howard, K. J., IEEE Trans. Mag. 31, 2737 (1995).Google Scholar
5. Wierman, K. W., Platt, C. L., Howard, J. K., and Spada, F. E., J. Appl. Phys. 93, 7160 (2003).10.1063/1.1555893Google Scholar
6. Maeda, T., Kai, T., Kikitsu, A., Nagase, T., and Akiyama, J.-I., Appl. Phys. Lett, 80, 2147 (2002).10.1063/1.1463213Google Scholar
7. Takahashi, Y. K., Ohnuma, M., and Hono, K. J., J. Magn. Magn. Mat. 246, 259 (2002).10.1016/S0304-8853(02)00065-3Google Scholar
8. Platt, C. L., Wierman, K. W., Svedberg, E. B., van de Veerdonk, R., Howard, J. K., Roy, A. G., and Laughlin, D. E., J. Appl. Phys. 92, 6104 (2002).10.1063/1.1516870Google Scholar
9. Barmak, K., Kim, J., Berry, D. C., Hanani, W. N., Wierman, K., Svedberg, E. B., and Howard, J. K., J. Appl. Phys. 97, 024902–1 (2005).Google Scholar
10. Berry, D. C., Kim, J., Barmak, K., Wierman, K., Svedberg, E. B., and Howard, J. K., Scripta Mater. 53, 423 (2005).10.1016/j.scriptamat.2005.04.026Google Scholar
11. Johnson, W. A. and Mehl, R. F., Trans. Am. Crystallogr. Assoc. 135, 416 (1939).Google Scholar
12. Avrami, M., J. Phys. Chem. 7, 1103 (1939).10.1063/1.1750380Google Scholar
13. Avrami, M., J. Phys. Chem. 8, 212 (1940).10.1063/1.1750631Google Scholar
14. Avrami, M., J. Phys. Chem. 9, 177 (1941).10.1063/1.1750872Google Scholar
15. Kolmogorov, A. N., Izv. Akad. Nauk SSR Ser. Fiz. Mat. Nauk 3, 355 (1937) (in Russian).Google Scholar
16. Jeong, S., McHenry, M. E., and Laughlin, D. E., IEEE Trans. Mag. 37, 1309 (2001).10.1109/20.950826Google Scholar
17. Berry, D. C. and Barmak, K., ” J. Appl. Phys. [in press].Google Scholar
18. Michaelsen, C., Barmak, K. and Weihs, T. P., J. Phys. D, 30, 3167 (1997).10.1088/0022-3727/30/23/001Google Scholar
19. Kissinger, H. E., US Bur Standards- J. Research 57, 217 (1956).10.6028/jres.057.026Google Scholar
20. Michaelsen, C. and Dahms, M., Thermochimica Acta 288, 9 (1996).10.1016/S0040-6031(96)03039-0Google Scholar
21. Binary Allloy Phase Diagrams, 2nd ed., edited by Massalski, T. B., Okamoto, H., Subramanian, P. R., and Kacprzak, L.. (ASM International, Materials Park, OH, 1990).Google Scholar
22. Christian, J. W., The Theory of Transformations in Metals and Alloys, 2nd ed. (Pergamon Press, New York, 1975), p. 8, 479.Google Scholar
23. Porter, D. A. and Easterling, K. E., Phase Transformations in Metals and Alloys, 2nd ed. (Chapman and Hall, New York, 1992), p. 11, 143, 157, 265–267.10.1007/978-1-4899-3051-4Google Scholar
24. Zeldovich, J. B., Acta Physicochimica U.R.S.S. 18, 1 (1943).Google Scholar
25. Barmak, K., Kim, J., Shell, S., Svedberg, E. B., and Howard, J. K., Appl. Phys. Lett. 80, 4268 (2002).10.1063/1.1483924Google Scholar
26. Shahmiri, M., Murphy, S., and Vaughan, D. J., Mineral. Mag. 49, 547 (1985).10.1180/minmag.1985.049.353.08Google Scholar
27. Kushida, A., Tanaka, K., Nakamura, H., Mater. Trans. 44, 59 (2003).10.2320/matertrans.44.59Google Scholar
28. Nosé, Y., Ikeda, T., Nakajima, H., Tanaka, K. and Nakamura, H., Mat. Res. Soc. Symp. Proc. 753, 381 (2003).Google Scholar
29. Kučera, J. and Million, B., Phys. Stat. Sol. A 31, 275 (1975).10.1002/pssa.2210310131Google Scholar