Microstructure and tribological properties of LaxCeyO1 − x − y composite nanofilms

A series of La_xCe_yO_{1 ? x ? y} films (x = 0–0.54, y = 0–0.58) with thickness of 35–45 nm was deposited by unbalanced magnetron sputtering. High-resolution transmission electron microscope observation shows that La_0.24Ce_0.34O_0.42 film has polycrystalline structure. La₂O₃ and CeO₂ are formed within the La_xCe_yO_{1 ? x ? y} films confirmed by the X-ray diffraction and X-ray photoelectron microscopy. The friction coefficient and residual compressive stress of five kinds of three-element compound films exhibit symmetric distribution with the relative equilibrium of La and Ce atomic concentration within the films. The critical load of all deposited films is between 28 and 33 mN. The friction coefficient of two kinds of rare earth complex oxide films is in the range of 0.08–0.09, which is lower than that of only one kind of rare earth oxide films, and the friction mechanism is discussed.