Oxidation of tungsten nanoclusters

• Published in: Thin solid films Vol. 444; no. 1; pp. 9 - 16
• Main Authors: Gillet, M., Mašek, K., Lemire, C.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.11.2003; Elsevier Science
• Subjects: Atomic force microscopy; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Nanoscale materials and structures: fabrication and characterization; Physics; Reflection high-energy electron diffraction; Tungsten oxide; Tungsten thin film; Tungsten oxide; Atomic force microscopy; Reflection high-energy electron diffraction; Tungsten thin film; Inorganic compounds; Epitaxial layers; Crystal orientation; Transition element compounds; Tungsten oxides; Nanostructures; Experimental study; Heat treatments; Substrates; Orientation relation; Thin films; Tungsten; Heterojunctions; Oxidation; Thermal annealing; Ultrahigh vacuum; Atomic clusters
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/S0040-6090(03)00907-6

The tungsten oxide nanoclusters were prepared by oxidation of epitaxialy grown tungsten thin film. The structure and morphology of tungsten and tungsten oxide nanoclusters were determined by RHEED (Reflection High-Energy Electron Diffraction) and AFM (Atomic Force Microscopy). The crystallographic structure and epitaxial relationships were evaluated. Annealing at the temperatures of 950 °C and 1150 °C gave rise to the tungsten clusters having (110) and (111) epitaxial planes, respectively. The two phases of tungsten oxide—WO 2 and WO 3—were found in dependence of oxidation conditions. The oxide clusters were epitaxially oriented on the α-Al 2O 3 substrate. The epitaxial orientations were deduced from the RHEED pattern and the surface distribution of clusters was characterised by AFM.