“…Many experimental techniques have been developed to evaluate Young's modulus of thin films, including nanoindentation testing (Ruud et al, 1994;Choi et al, 2003;Son et al, 2003), X-ray diffraction with in situ tensile testing (Villain et al, 2002;Renault et al, 2003) and laser-ultrasonic surface acoustic wave spectrometry (Hurley et al, 2001). Some experiments (Yang et al, 1977;Baral et al, 1985;Renault et al, 2003;Cuenot et al, 2004) show the increase in elastic modulus as the constituent film size decreases while other experiments (Petersen and Guarnieri, 1979;Ruud et al, 1994;Hurley et al, 2001;Villain et al, 2002) show the opposite trend. In addition to the experimental investigations, MD simulations based on either pair potentials or many body potentials have been carried out to study this size dependence for ultrathin films (Streitz et al, 1990(Streitz et al, , 1994Wolf, 1991;Zhou and Huang, 2004).…”