Europhys. Lett., 57 (6) , pp. 866-871 (2002)
Strongly enhanced tunneling magnetoresistance in granular films of clusters in a matrix: Evidence for a cluster-surface/matrix interactionH. Zare-Kolsaraki, B. Hackenbroich and H. Micklitz
II. Physikalisches Institut, Universität zu Köln Zülpicher Str. 77, 50937 Köln, Germany firstname.lastname@example.org
(Received 8 October 2001; accepted in final form 7 January 2002)
A new granular system, namely, clusters embedded in solid , has been prepared by the co-deposition of well-defined clusters (mean diameter , and molecules onto a cold substrate. This system shows a temperature-dependent tunneling magnetoresistance (TMR) which has a value of 31(2)% at 2.5 . Using Jullière's model this value corresponds to a spin-polarisation |P| = 0.68(2) of the tunneling electrons, compared to P = 0.42 for granular or planar . We interpret this enhancement of P as caused by a cluster-surface/matrix interaction.
72.15.Gd - Galvanomagnetic and other magnetotransport effects.
73.40.Gk - Tunneling.
73.40.Rw - Metal-insulator-metal structures.
© EDP Sciences 2002