COMPOSITION-DEPENDENT STRUCTURAL, OPTICAL, MECHANICAL, AND MOISTURE RESISTANT PROPERTIES OF CAF2-TIO2 COMPOSITE FILMS PREPARED BY REACTIVE ION-ASSISTED CODEPOSITION

The influences of TiO2 contents on the structural, optical, mechanical , and moisture resistant properties of CaF2-TiO2 composite films prepa red by reactive ion-assisted codeposition are systematically investiga ted. The CaF2 films deposited at an ambient substrate temperature are found to have superior optical, mechanical, and moisture resistant pro perties with the addition of 10 at. % TiO2, The structure of this film changes from polycrystalline CaF2 to a mixed phase of amorphous TiO2 and polycrystalline CaF2, The hardness of composite films containing 4 5 at, % TiO2 is even higher than that of pure TiO2 and glass, which is attributed to the isolation of the crystalline CaF2 grains by the int erconnection of the amorphous TiO2 dispersoids. (C) 1998 Society bi Ph oto-Optical instrumentation Engineers.