Surface morphology-controlled fabrication of Na2WO4 films with high structural stability.

Films with designed surface morphologies are of great importance for high-performance devices and other applications such as gas sensors and catalysts. Na 2 WO 4 films with various surface morphologies have been fabricated via physical evaporation inside the chamber created by approaching mouth to mouth two alumina boats containing precursors and by covering alumina boat with aluminum foil, respectively. The temperature-dependence Raman investigation reveals red shifting of the Raman peaks with increasing temperature in all cases. The observed Raman shifts are relatively small confirming high stability of the Na 2 WO 4 films within the investigated temperature range. [ABSTRACT FROM AUTHOR]