Synthesis and characterization of Y_2O_3 nanoparticles and nanorods in magnetron sputtered Ti-Y alloy films

摘要

Y_2O_3 nanoparticles and nanorods have been firstly synthesized in bulk Ti-Y films prepared by magnetron sputtering on Si (100) substrates at different temperatures. X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS) are used to characterize the structure, morphology, and composition of the as-synthesized nanoparticles and nanorods. The mechanical properties of the sputtered films are investigated using nanoindentation techniques. The results indicate that both the nanoparticles and nanorods have a pure cubic Y_2O_3 structure resulting from the reaction of Y atoms with the residual O_2 in the vacuum chamber, and are free from defects and dislocations with uniform diameters of about 30 nm. The Y_2O_3 nanoparticles mainly distribute at the grain boundaries of the Ti matrix and the nanorods have engths ranging from 250 nm to more than 1 μm with the growth direction parallel to the (002) plane. As the growth temperature elevates, the nanoparticles turn to be coarsening while more and longer nanorods are inclined to form. Compared with the Ti film, the TiY films have a remarkable increase in hardness, but do not exhibit expected increase in elastic modulus. Finally, the growth mechanism is also briefly discussed.