The effect of thermal annealing in an inert atmosphere (argon) on the structural and thermochromic properties of MoO 3 thin films was investigated. MoO 3 thin films were deposited by thermal evaporation in vacuum of MoO 3 powders. X-ray diffraction patterns of the films showed the presence of the monoclinic Magneli phase Mo 9O 26 for annealing temperatures above 250∘C. Absorbance spectra of the films annealed in argon indicated that their thermochromic response increases with the annealing temperature in the analyzed range (23 ∘C –300 ∘C), a result opposite to the case of thermal annealings in air, for which case the thermochromic response shows a maximum value around 200 ∘C–225 ∘C and decreases for higher temperatures. These results are explained in terms of a higher density of oxygen vacancies formed upon thermal treatments in inert atmospheres.
Bibliographical noteFunding Information:
The technical assistance of E. Ayala, M. Guerrero, and A. García is acknowledged. This work was partially supported by Consejo Nacional de Ciencia y Tecnologia (CONACyT) under Projects No. 168605 and 205733.
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All Science Journal Classification (ASJC) codes
- Condensed Matter Physics