Structural and spectroscopic characterization of irreversible phase changes in rapidly heated precursors of europium-doped titania nanoparticles

摘要

AbstractWe observe temperature-dependent phase changes in a precursor of europium-doped titania (p-Eu:TiO2) that is prepared via precipitation and is laser-heated to temperatures between 473K and 1246K within sub-second heating durations. The phase changes are characterized using X-ray diffraction and site-selective photoluminescence spectroscopy. We find that upon heating, the initially amorphous p-Eu:TiO2first transforms into the anatase phase and then into a mixed anatase/rutile phase. These phase transformations change the local environment of the dopant Eu3+ions resulting in modifications to the Eu3+ions spectroscopic properties, with the modifications occurring for calcination temperatures above approximately 573K following sub-second durations. These results demonstrate the temperature sensing ability of p-Eu:TiO2nanoparticles for use in sub-second heating events. Moreover, at 573K this temperature is lower than other host materials that we have evaluated (i.e., La2O3, ZrO2and Y2O3).Graphical abstractThe as-prepared europium doped titania (p-Eu:TiO2) nanopar