ELASTIC PROPERTIES OF METALLIC THIN FILMS: 2D SYNCHROTRON XRD ANALYSIS DURING IN SITU TENSILE TESTING G. Geandier, 1 P.-O. Renault, 1 S. Teat, 2 P. Goudeau, 1 and E. Le Bourhis 1 1 LMP-UMR 6630 CNRS, Université de Poitiers, SP2MI, Boulevard Marie et Pierre Curie, BP30179, 86962 Futuroscope Chasseneuil, France 2 ALS–LBNL, 1 Cyclotron Road, Mail Stop 2-400, Berkeley, California 94720 ABSTRACT Elastic behavior of thin films studied from in situ loading of the specimen during X-ray diffraction on a synchrotron source is presented. Model nanometric multilayer W/Au systems exhibiting different microstructures were analyzed. These films are supported by a (thin) polyimide substrate. X-ray diffraction in transmission geometry was used to study the deformations of both phases as a function of applied load. This geometry was developed with the aim of optimizing experiment time. Using 2D detectors and dynamical loading, measuring time is reduced considerably, down to a few hours compared to a one-week experiment in a laboratory. Furthermore, the in-plane strain state is measured in all directions with great precision. INTRODUCTION Understanding the mechanical behavior of nanostructured thin films in relation to their microstructure, in particular to the grain size, is of high importance for the development of technological applications. For a few years, there has been increasing interest in the elastic properties of thin films [1–4]. Literature data seem to show that the elastic behavior of metallic thin films can differ significantly from their bulk counterparts because of their specific microstructure (texture, defects, high density of interface, and interface mixing) and of size effects (i.e. period thickness) [5–8]. Studying and tailoring the size effect on elastic constants of polycrystalline thin films require controlling the nanostructure (grain size, residual stresses, and texture). One way to control grain size along one direction at nanometric scales is to prepare multilayers. Elastic behavior of supported thin films can be determined by combining tensile test [9–11] or four point bending [12–14] and X-ray diffraction (XRD). XRD is phase selective and therefore a unique technique that allows determination of both the mechanical and microstructural states of the diffracting phases. This technique can be used to study how the elastic constants are affected by the period thickness independently of the multilayer components. The main disadvantage of the XRD technique is that the X-ray measurements are time consuming for thin multilayers (as the diffracting volume is quite small) even for high-flux synchrotron radiation sources. The aim of this paper is to show how the elastic behavior of multilayers can be studied from the in situ loading of the specimen during the X-ray diffraction experiment. We report a tensile test study of W/Au multilayers films deposited on kapton substrate. As the X-ray strain 169 Copyright ©JCPDS-International Centre for Diffraction Data 2008 ISSN 1097-0002