Claudio Vinegoni, Ph.D. | Raman study of the phase transitions sequence in pure WO3 at high temperature and in HxWO3 with variable hydrogen content

Solid State Ion.
Raman study of the phase transitions sequence in pure WO3 at high temperature and in HxWO3 with variable hydrogen content

Cazzanelli^#, E., Vinegoni, C., Mariotto, G., Kuzmin, A., and Purans, J.

Solid State Ionics 1999

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An extensive investigation of the temperature dependence of Raman spectra has been carried out on WO3 powders from room temperature to 800 degrees C. In particular the orthorhombic-to-tetragonal phase transition occurring at about 740 degrees C has been studied for the first time. The Raman active mode at 710 cm(-1) of the orthorhombic phase disappears from the spectrum at temperature below the phase transition point and the Raman activity in the tetragonal phase results very low. A comparative study of hydrogenated tungsten bronzes HxWO3 (x less than or equal to 0.23), where the same transition sequence is driven by an increase of the proton concentration from x = 0 to 0.23, reveals similar behaviour of the high frequency Raman active modes, which are better resolved due to the weaker anharmonic interactions. (C) 1999 Elsevier Science B.V. All rights reserved.
@article{1999-SSI, author= {Cazzanelli<sup>#</sup>, E. and Vinegoni, C. and Mariotto, G. and Kuzmin, A. and Purans, J.}, title= {Raman study of the phase transitions sequence in pure WO3 at high temperature and in HxWO3 with variable hydrogen content}, journal= {Solid State Ionics}, alternatejournal = {Solid State Ion.}, year = {1999}, volume = {123}, number = {1-4}, pages = {67-74}, issn = {0167-2738}, doi = {10.1016/s0167-2738(99)00101-0}, }
10.1016/s0167-2738(99)00101-0

Abstract

"An extensive investigation of the temperature dependence of Raman spectra has been carried out on WO3 powders from room temperature to 800 degrees C. In particular the orthorhombic-to-tetragonal phase transition occurring at about 740 degrees C has been studied for the first time. The Raman active mode at 710 cm(-1) of the orthorhombic phase disappears from the spectrum at temperature below the phase transition point and the Raman activity in the tetragonal phase results very low. A comparative study of hydrogenated tungsten bronzes HxWO3 (x less than or equal to 0.23), where the same transition sequence is driven by an increase of the proton concentration from x = 0 to 0.23, reveals similar behaviour of the high frequency Raman active modes, which are better resolved due to the weaker anharmonic interactions. (C) 1999 Elsevier Science B.V. All rights reserved."

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For attribution in academic contexts, please cite this work as:

Cazzanelli^#, E., Vinegoni, C., Mariotto, G., Kuzmin, A., & Purans, J. (1999). Raman study of the phase transitions sequence in pure WO3 at high temperature and in HxWO3 with variable hydrogen content. Solid State Ionics, 123(1-4), 67–74. https://doi.org/10.1016/s0167-2738(99)00101-0