Investigation of elastic and optical properties of electron beam evaporated ZrO2-MgO composite thin films

Thin films of composite materials are being progressively explored for achieving tunability in the optical constants for application in multilayer optical devices. In the present study, a set of ZrO2-MgO binary mixed composite thin films have been prepared by reactive electron beam evaporation of solid solution of ZrO2 and MgO at different oxygen partial pressures. Since elastic properties of the thin films are very important for their environmental stability under high power laser application, elastic moduli (indentation moduli) of the films have been measured by atomic force acoustic microscopy measurements. The optical properties especially refractive index of such films has been determined from the optical transmission measurement using an inverse synthesis method, while the density of such films has been measured by grazing incidence X-ray reflectivity. The variation of the elastic moduli of the thin films as a function of oxygen partial pressure used during deposition has been studied and the above variation has been corroborated with the variation of density and refractive index of the thin films.