Determination of the plane stress elastic constants of thin films from substrate curvature measurements: Applications to amorphous metals

A new method for measuring the static plane stress elastic constants of thin films on a substrate is described. It is based on measurements of the principal curvatures of two identical samples deposited on substrates with different preset curvatures. It is accurate if the deposition stress is no larger than the stress due to the bending of the substrates. Young’s modulus and Poisson’s ratio of amorphous Pd78Si22 were found to be the same as those of melt-spun material. The biaxial modulus of amorphous PdSi/PdSiFe multilayers was found to be independent of the bilayer repeat length.