Beam model for calculating magnetostriction strains in thin films and multilayers

A standard technique to measure the magnetostriction strain in thin films i nvolves measurement of the end deflection or slope of cantilever beams usin g optical deflectometry or capacitive methods. This article presents a gene ral beam model for inferring magnetostriction strain from the end deflectio n or slope data. This model greatly extends the range of applicability over existing shell models, allowing for inference of magnetostriction strains for practical film/substrate thickness ratios that are important in microel ectromechanical systems (MEMS) and bio-microelectromechanical systems (bio- MEMS). If the properties of individual layers are known, the beam theory ca n be used to design multilayer MEMS or bio-MEMs beams over a full range of thickness ratios. (C) 2001 American Institute of Physics.