Investigation of an anisotropic plate model to evaluate the interface adhesion of thin film with cross-sectional nanoindentation method

Cross-sectional nano-indentation is a new technology especially designed for measuring interface adhesion of thin film with nano-indenter and atomic force microscopy or scanning electron microscopy. In the paper, the delamination area induced by nano-indenter pressing on the cross-section of multiple-layer thin film structure was regarded as a semi-circular interfacial crack system, and thin film delaminated from the oxide-layer/substrate composite assumed as rigid was simplified as a bending circular plate. Based on the anisotropic plate theory, in which the effect of transverse shear is considered, the analytical relationship of the critical energy release rates per unit new crack with the radii of interfacial crack area, the size of oxide-layer/substrate composite extrapolated, and the displacement of thin film extrapolated by the indenter was derived. As example, the interfacial adhesion of BaTiO3, CoFe2O4, and PZT-4 thin films evaluated by the anisotropic plate and the previous tapered beams models were simulated and discussed.