MEASUREMENT OF LATTICE STRAIN IN AU-NI MULTILAYERS AND CORRELATION WITH BIAXIAL MODULUS EFFECTS

Measurement of lattice strain within each atomic plane of sputter-deposited, gold-nickel multilayer films is accomplished using x-ray diffraction and high resolution electron microscopy. Experimental determination of strain along the composition modulation direction [1 - 1 1] from x-ray diffraction scans fit to dynamical theory compare well with values measured from high-resolution electron micrographs and selected-area-diffraction patterns. The measured strain in-plane (2 2 0) and along the composition modulation (1 - 1 1) reveal the gold layers to be in compression and the nickel layers in tension. The experimental strain values are used within the framework of the "coherency strain model" to predict an enhancement of the biaxial elastic modulus Y(111), which is in good agreement with the original experimental measurements on thermal-evaporated films.