Influence of the target morphology on anisotropic GMR of Cu-Co laser ablated thin films

A correlation between the structure of the target surface and the magneto-transport properties of pulsed laser ablated Cu-Co thin films is presented in this work. During the deposition process, if the target rotation velocity is kept at 7 rpm, craters and cones, with an average roughness of 9 mu m, appear on the target surface after 15 min deposition time. A post-deposition annealing induces the appearence of giant magneto-resistance in the films, and coercivities up to 1700 Oe. However, as the target rotation speed is increased up to 32 rpm, more craters and cones are present on the surface but its average rugosity decreases to 8 mu m. The maximum coercivity for the samples deposited in these conditions is 1100 Oe. A possible mechanism to explain this behavior is discussed. (C) 1999 Published by Elsevier Science B.V. All rights reserved.