Study of the mechanical characteristics of the Al₂O₃ film on the LiNbO₃ substrate

Abstract

The microhardness of a thin aluminum oxide film with a thickness of 80 to 240 nm on the surface of a lithium niobate single crystal was determined by the method of nanoindentation. The hardness and Young’s modulus for a film deposited by dc-magnetron sputtering of an aluminum target in a gas (Ar+O2) medium were more than 30 GPa and 300 GPa, respectively. The dependences of the film thickness on the mechanical properties of a layered system, in particular hardness and elastic modulus, were established.