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Thermodynamic Evaluation of the Interface Stability Between Selected Metal Oxides and Co

Published online by Cambridge University Press:  03 March 2011

Ying Yang*
Materials Science and Engineering Department, University of Wisconsin, Madison, Wisconsin 53706
Peter F. Ladwig
Materials Science Program, University of Wisconsin, Madison, Wisconsin, 53706
Y. Austin Chang
Materials Science and Engineering Department and Materials Science Program, University of Wisconsin, Madison, Wisconsin 53706
Feng Liu
Recording Head Operations, Seagate Technology, Bloomington, Minnesota 55435
Bharat. B. Pant
Recording Head Operations, Seagate Technology, Bloomington, Minnesota 55435
Allan E. Schultz
Recording Head Operations, Seagate Technology, Bloomington, Minnesota 55435
a)Address all correspondence to this author.
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For an interface to be considered thermodynamically stable, the phases in contact must be in equilibrium with each other (connected by a stable tie-line) and have negligible mutual solubility on the phase diagram. The stability of Co based magnetic tunnel junctions (MTJs), with Co/MxO1-x/Co structures (M = Al, Gd, Hf, La, Mg, Si, Ti, Ta, Y and Zr), were evaluated with regard to these two conditions. Specifically, low temperature ternary isothermal phase diagrams were calculated and evaluated for the Co–M–O systems. All of these systems have at least one oxide in equilibrium with Co and thus have at least one thermodynamically stable tunnel barrier candidate for use in Co based MTJs. In light of the assumptions made in this analysis, along with the uncertainty in applying bulk enthalpy data to thin films, the current evaluation of interfacial stability serves as a first step in identifying suitable stable tunneling barrier materials in MTJs for detailed study.

Copyright © Materials Research Society 2004

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1Smith, D.J., McCartney, M.R., Platt, C.L. and Berkowitz, A.E.: J. Appl. Phys. 83, 5154 (1998).CrossRefGoogle Scholar
2Moodera, J.S., Nassar, J. and Mathon, G.: Annu. Mater. Sci. 29, 381 (1999).CrossRefGoogle Scholar
3Platt, C.L., Dieny, B. and Berkowitz, A.E.: Appl. Phys. Lett. 69, 2291 (1996).CrossRefGoogle Scholar
4Wang, J., Freitas, P.P., Snoeck, E., Wei, P. and Soares, J.C.: Appl. Phys. Lett. 79, 4387 (2001).CrossRefGoogle Scholar
5Rottländer, P., Hehn, M., Lenoble, O. and Schuhl, A.: Appl. Phys. Lett. 78, 3274 (2001).CrossRefGoogle Scholar
6Leclair, P., Moodera, J.S. and Meservey, R.: J. Appl. Phys. 76, 6546 (1994).CrossRefGoogle Scholar
7Schlom, D.G. and Haeni, J.H.: MRS Bull. 27, 198 (2002).CrossRefGoogle Scholar
8Klingbeil, J. and Schmid-Fetzer, R.: J. Phase Equilibria. 13, 522 (1992).CrossRefGoogle Scholar
9de Boer, F.R., Boom, R., Mattens, W.C.M., Miedema, A.R. and Niessen, A.K.: Cohesion in Metals, Transition Metal Alloy (Elsevier, North-Holland, Amsterdam, The Netherlands, 1988)Google Scholar
10Waldner, P. and Eriksson, G.: Calphad. 23, 189 (1999).CrossRefGoogle Scholar
11Wartenberg, H.V. and Prophet, E.: Z. Anorg. U. Allgem. Chem. 208, 379 (1932).Google Scholar
12Knacke, O., Kubaschewski, O. and Hesselmann, K.: Thermochemical Properties of Inorganic Substances, 2nd ed. (Springer-Verlag, Düsseldorf, Germany; Verlag Stahleisen, Berlin, Germany and New York, 1991)Google Scholar
13Elliott, R.P.: Constitution of Binary Alloys, First Supplement, McGraw-Hill Series in Materials Science and Engineering (McGraw-Hill, Amsterdam, The Netherlands, 1965)Google Scholar
14Chen, E.Y., Whig, R., Slaughter, J.M., Cronk, D., Goggin, J., Steiner, G. and Tehrani, S.: J. Appl. Phys. 87, 6061 (2000).CrossRefGoogle Scholar
15Ma, E., Sheng, H.W., He, J.H. and Schilling, P.J.: Mater. Sci. Eng. A. 286, 48 (2000).CrossRefGoogle Scholar
16Liu, B.X., Lai, W.S. and Zhang, Q.: Materials Science and Engineering. R 29, 1 (2000).Google Scholar
17Ladwig, P.F., Olson, J.D., Bunton, J.H., Larson, D.J., Ulfig, R.M., Martens, R.L., Oltman, E., Bonsager, M.C., Gribb, T.T., Kelly, T.F., Schultz, A.E., Pant, B.B., and Chang, Y.A.: (2003, unpublished).Google Scholar
18Bobeth, M., Hecker, M., Pompe, W., Schneider, C.M., Thomas, J., Ullrich, A. and Wetzig, K.: Z. Metallkd. 92, 810 (2001).Google Scholar
19Knoedler, H.L., Lucas, G.E. and Levi, C.G.: Metall. Mater. Trans. 34 A,1043 (2003).Google Scholar
20Yokokawa, H., Kawada, T. and Dokiya, M.: J. Am. Ceram. Soc. 72, 2104 (1989).CrossRefGoogle Scholar
21Liu, Z-K. and Chang, Y.A.: Calphad. 23, 339 (1999).CrossRefGoogle Scholar
22Kitayama, K.: J. Am. Ceram. Soc. 75, 1447 (1992).CrossRefGoogle Scholar
23Liu, Z-K., Zhang, W. and Sundman, B.: J. Alloys Compd. 226, 33 (1995).CrossRefGoogle Scholar
24Kitayama, K.: J. Solid State Chem. 76, 241 (1988).CrossRefGoogle Scholar
25Wu, C.H. and Chuang, Y.C.: J. Phase Equilibria. 12, 587 (1991).CrossRefGoogle Scholar
26Gachon, J.C. and Hertz, J.: Calphad. 7, 1 (1983).CrossRefGoogle Scholar