Three-dimensional atom probe studies of metallic multilayers

Multilayer film structures which exhibit giant magnetoresistance have applications in the areas of magnetic recording and computer memory. The magnetic properties of these structures are highly dependent upon atomic level structural and compositional variations. Thus. structural characterization with extremely high spatial resolution, especially at the interfaces, is very important in order to optimize the performance of these devices with respect to processing and operating conditions. Field-ion microscopy and three-dimensional atom probe microanalysis have been used to characterize the interfaces and grain boundaries in a structure containing 100 repetitions of a (Cu-2 (nm)/Co-2 (nm)) bilayer. Analyses show layer alloying, a high degree of layer curvature (particularly close to grain boundaries) and regions where cobalt layers are in contact. In addition, atomic scale analysis of the interface bt tween copper and cobalt layers indicates that atomic planes are coherent from one layer to the next. (C) 1999 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved