Thermal stability of reactive sputtered tungsten oxide coatings

• Author(s): Parreira, N. M. G. ; Polcar, T. ; Cavaleiro, A.
• Date: 2007
• Persistent ID: http://hdl.handle.net/10316/4205
• Origin: Estudo Geral - Universidade de Coimbra
• Subject(s): Tungsten oxide; Reactive sputtering; Structural characterization; Thermal stability
• Document Type: Article
• Language: English

Description

The thermal stability of different W-O coatings, W100, W90O10, W54O46, W30O70 and W25O75, were studied by in-situ X-ray diffraction at elevated temperatures up to 900 °C. The coatings were deposited by DC reactive magnetron sputtering from a pure tungsten target in an Ar + O2 atmosphere onto Fecralloy alloy. The evolution of the structure of the coatings was studied in both protective and oxidant atmospheres. Three groups of films were identified: (1) W25O75 which showed structural evolution following the W-O phase diagram; (2) amorphous O-deficient WO3 whose structure followed the W-O phase diagram either as WO3 or as its chemical composition depending on annealing in oxidant or protective atmospheres, respectively; and (3) low O-content crystalline films that oxidized from 500 °C. http://www.sciencedirect.com/science/article/B6TVV-4MV74W9-1/1/f13fd19171ebf6554fff185464ae87e1