2018/10/02 by E. Besozzi, Besozzi, Edoardo, D. Dellasega +7
Engineering · Materials Science · #Diamond and Carbon-based Materials Research #FOS: Physical sciences #High-Temperature Coating Behaviors #Materials Science (cond-mat.mtrl-sci) #Metal and Thin Film Mechanics
paper · pdf · doi:10.48550/arxiv.1810.01201
openalex publication_date 2018/10/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this work, we investigate the correlation between morphology, composition,\nand the mechanical properties of metallic amorphous tungsten-oxygen and\namorphous tungsten-oxide films deposited by Pulsed Laser Deposition. This\ncorrelation is investigated by the combined use of Brillouin Spectroscopy and\nthe substrate curvature method. The stiffness of the films is strongly affected\nby both the oxygen content and the mass density. The elastic moduli show a\ndecreasing trend as the mass density decreases and the oxygen-tungsten ratio\nincreases. A plateaux region is detected in correspondence of the transition\nbetween metallic and oxide films. The compressive residual stresses, moderate\nstiffness and high local ductility that characterize compact amorphous\ntungsten-oxide films make them promising for applications involving thermal or\nmechanical loads. The coefficient of thermal expansion is quite high (i.e. 8.9\n\⋅ 10-6 K-1), being strictly correlated to the amorphous\nstructure and stoichiometry of the films. Under thermal treatments they show a\nquite low relaxation temperature (i.e. 450 K). They crystallize into the\n\γ monoclinic phase of WO3 starting from 670 K, inducing an increase\nby about 70 % of material stiffness.\n