Phase transformation and photoluminescence of undoped and Eu 3+ -doped zinc stannate (Zn 2 SnO 4 ) nanocrystals synthesized by hydrothermal method

In this work we report a hydrothermal approach for synthesis of zinc stannate (Zn 2 SnO 4 –ZTO) nanocrystals. Structural properties and morphology of the samples were investigated in detail. In particular, our research focused on the effect of hydrothermal duration on the phase composition of ZTO nanocrystals. By combining X-ray diffraction analysis, scanning electron microscopy and selected area energy-dispersive X-ray spectroscopy, a crystalline phase transformation during the hydrothermal process was enlightened. The ZTO nanocrystals were doped with europium ions. The room-temperature emission spectra of the undoped ZTO and Eu 3+ -doped ZTO nanocrystals were recorded. The emission spectra of the undoped ZTO nanocrystals showed two broad bands related to the lattice defects, while the spectra of Eu 3+ -doped ZTO nanocrystals exhibited the narrow emission peaks, which were assigned to the radiative intra-configurational f–f transitions of Eu 3+ ions.