Thin films of TiO2-Ge nanocomposites were deposited by rf magnetron sputtering from a composite target prepared by pressing a mixture of TiO2 and Ge powders with a ratio 2:1. Thin films were deposited at various rf powers and temperatures and characterized by using x-ray diffraction, x-ray photoelectron spectroscopy, and transmission electron microscopy (TEM). The analyses showed that the film composition changes with the target rf power and substrate temperature with rf power being a bigger contributor to the change. TEM analyses of films revealed that segregated Ge nanograins were formed and were dispersed within the TiO2 matrix. The average grain size of Ge nanograins was between 9 and 15 nm. (c) 2008 American Vacuum Society.