Phase transition in WO3 microcrystals obtained by sintering process

The vibrational properties of WO3 ceramics in the 30–300 K temperature range were probed by Raman spectroscopy. Starting with WO3 ceramics at room temperature presenting monoclinic (V) and triclinic (VI) mixed phases, structural transitions related to decreasing temperature were observed. At low temperatures a monoclinic (VII) and a new mixed phase were observed, the former characteristic of WO3 bulk and the latter associated to microcrystals. The analysis of the spectra indicated that the new phase develops gradually and it comes mainly from the monoclinic (V) phase. Copyright © 2001 John Wiley & Sons, Ltd.

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