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In situ X-ray absorption spectroscopy study of the thermal behaviour of giant magnetoresistance CoxAg1−x and NixAg1−x heterogeneous alloys

Published online by Cambridge University Press:  15 February 2000

O. Proux*
Affiliation:
CEA, Département de Recherche Fondamentale sur la Matière Condensée, SP2M, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
J. R. Regnard
Affiliation:
CEA, Département de Recherche Fondamentale sur la Matière Condensée, SP2M, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France Université Joseph Fourier, B.P. 53 X, 38041 Grenoble Cedex, France
I. Manzini
Affiliation:
CEA, Département de Recherche Fondamentale sur la Matière Condensée, SP2M, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
C. Revenant
Affiliation:
CEA, Département de Recherche Fondamentale sur la Matière Condensée, SP2M, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
B. Rodmacq
Affiliation:
CEA, Département de Recherche Fondamentale sur la Matière Condensée, SP2M, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
J. Mimault
Affiliation:
Laboratoire de Métallurgie Physique, SP2MI, Bd. Marie et Pierre Curie, Téléport 2, B.P. 179, 86960 Futuroscope Cedex, France
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Abstract

Heterogeneous CoxAg1−x and NixAg1−x alloys have giant magnetoresistance properties. Such alloys, with atomic concentrations x = 0.20 and 0.37, were studied by transmission X-ray Absorption Spectroscopy at the Co or Ni K-edge after in situ thermal annealing. For alloys as-deposited and annealed at 200 °C, Extended X-ray Absorption Fine Structure analysis displays both Co-Co (Ni-Ni) bonds related to Co (Ni) atoms agglomerated in magnetic particles and Co-Ag (Ni-Ag) bonds related to Co (Ni) atoms in substitutional sites in the Ag matrix. At the same alloy concentration, the miscibility in the Ag matrix is found larger for Ni than for Co. After annealing around 250 °C, the marked decrease of the Ag neighbour peak corresponds to a diffusion of magnetic atoms outside the Ag matrix. The Co-Co coordination number increases regularly with annealing temperatures up to 450 °C reflecting a progressive expansion of Co particles. On the contrary, for Ni alloys, no further particle expansion has been observed in the same annealing range. This different behaviour may be linked both to the difference between the as-deposited structural states and to the Co/Ag and Ni/Ag interfaces energies. Using a simple model, evolution of the mean particle size has been estimated as a function of annealing.

Keywords

Type
Research Article
Copyright
© EDP Sciences, 2000

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References

Berkowitz, A.E., Mitchell, J.R., Carey, M.J., Young, A.P., Zhang, S., Spada, F.E., Parker, F.T., Hutten, A., Thomas, G., Phys. Rev. Lett. 68, 3745 (1992). CrossRef
Xiao, J.Q., Jiang, J.S., Chien, C.L., Phys. Rev. Lett. 68, 3749 (1992). CrossRef
Cowache, C., Dieny, B., Teixeira, S.R, Redon, O., Phys. Met. Metallogr. 79, 61 (1995).
Regnard, J.R., Revenant-Brizard, C., Dieny, B., Mevel, B., Mimault, J., Mater. Res. Soc. Symp. Proc., Materials Research Society 400, 329 (1996). CrossRef
Regnard, J.R., Juanhuix, J., Brizard, C., Dieny, B., Mevel, B., Mimault, J., Proux, O., Solid State Commun. 97, 419 (1996). CrossRef
Revenant, C., Regnard, J.R., Mimault, J., Proux, O., Dieny, B., Mevel, B., J. Phys. IV France 7, C2-1111 (1997).
Borowski, M., J. Phys. IV France 7, C2-259 (1997).
Newville, M., Livins, P., Yacoby, Y., Rehr, J.J., Stern, E.A., Phys. Rev. B 47, 14126 (1993). CrossRef
B.K. Agarwal, X-Ray Spectroscopy an Introduction, 2nd edn. (Springer, Berlin, 1991).
Flores, W.H., Teixera, S.R., Geshev, J., da Cunha, J.B.M., Schilling, P.J., Traverse, A., Martins Al, M.C.ves, J. Magn. Magn. Mater. 188, 17 (1998). CrossRef
Du, H., Liu, W.J., Li, Q., Sang, H., Zhang, S.Y., Du, Y.W., Feng, D., J. Magn. Magn. Mater. 191, 17 (1999). CrossRef
Traverse, A., New J. Chem. 22, 677 (1998). CrossRef
Apai, G., Hamilton, J.F., Stohr, J., Thompson, A., Phys. Rev. Lett. 43, 165 (1979). CrossRef
Balerna, A., Bernieri, E., Picozzi, P., Reale, A., Santucci, S., Burattini, E., Mobilio, S., Phys. Rev. B 31, 5058 (1985). CrossRef
Dieny, B., Teixeira, S.R., Rodmacq, B., Cowache, C., Auffret, S., Redon, O., Pierre, J., J. Magn. Magn. Mater. 130, 197 (1994). CrossRef
Du, J.H., Li, Q., Wang, L.C., Sang, H., Zhang, S.Y., Du, Y.W., Feng, D., J. Phys.-Cond. Matter 7, 9425 (1995). CrossRef
Nagamine, L.C.C.M., Dieny, B., Rodmacq, B., Mevel, B., Regnard, J.R., Revenant, C., Manzini, I., J. Magn. Magn. Mater. 195, 437 (1999). CrossRef
Revenant-Brizard, C., Simon, J.P., Regnard, J.R., Manzini, I., Rodmacq, B., J. Appl. Cryst. 31, 783 (1998). CrossRef
Proux, O., Mimault, J., Revenant-Brizard, C., Regnard, J.R., Mevel, B., J. Phys.-Cond. Matter 11, 147 (1999). CrossRef
F.R. de Bor, R. Boom, W.C.M. Mattens, A.R. Miedama, A.K. Niessen, in Cohesion in metals, edited by F.R. de Bor, D. Pettifor (Amsterdam, Elsevier, 1988).
Fontaine, A., Lagarde, P., Naudon, A., Raoux, D., Spanjaard, D., Philos. Mag. B 40, 17 (1979). CrossRef
Boscherini, F., de Panfilis, S., Weissmüller, J., Phys. Rev. B 57, 3365 (1998). CrossRef
Khoutami, A., Legrand, B., Mottet, C., Tréglia, G., Surf. Sci. 307-309, 735 (1994). CrossRef
MacKay, A.L., Acta Cryst. 15, 916 (1962). CrossRef
Fritsche, H.G., Benfield, R.E., Z. Phys. D 26, 15 (1993). CrossRef
Hwang, R.Q., Phys. Rev. Lett. 76, 4757 (1996). CrossRef