Textures of Au, Pt and Pd/PdO nanoparticles thermally dewetted from thin metal layers on fused silica

Abstract

This article presents results concerning the basic dewetting procedure of thin metal films on an amorphous substrate. Thin layers of gold, platinum and palladium are deposited on fused silica glass sheets by sputtering. The 14 to 18 nm thick layers of Au, Pt and Pd are dewetted into nanoparticles (NP) at temperatures from 424 to 1600 °C. The morphology of the resulting NP is characterized using scanning electron microscopy (SEM) while crystallographic analyses are performed using electron backscatter diffraction (EBSD). Multiple textures are described to occur and coexist in NP-layers of the respective materials and a temperature dependence of the texture formation in gold NP is proved. The transformation of Pd to PdO and its effects on the texture is also analyzed. It is shown that the cooling rate has an effect on the texture in the case of gold NP as well as on the physical structure of the Pd/PdO NP. Twinning relationships could be described to occur on all samples.