Poisson’s ratio measurement in tungsten thin films combining an x-ray diffractometer with <i>in situ</i> tensile tester

Abstract

A direct determination of the Poisson’s ratio in 150 nm polycrystalline tungsten thin films deposited by ion-beam sputtering on Duralumin substrates has been performed by combining x-ray diffraction measurements with in situ traction on the sample. X-ray diffraction experiments using the sin2 ψ method have been done at LURE, the French synchrotron facility (Orsay, France) on a four-circle diffractometer. The method described in this letter allows us to extract in a simple way and with a good precision the Poisson’s ratio of thin films on substrates from the evolution of the sin2 ψ curves as a function of applied strains. In the case of tungsten thin film, the value obtained is close to the bulk material one.