Structural and optical studies of Eu³⁺ doped nanocrystalline tellurite glass

Abstract

A series of transparent glasses with composition (80-x) TeO2 - 15 MgO - (x) Eu2O3, over the concentration region of 0 - 2.5 mol% were obtained using conventional melt-quenching technique. The nanocrystalline glass samples were prepared by heating the as-cast glasses above the crystallization temperature. The amorphous nonocrystalline and crystalallized glass samples were characterized using X-ray diffraction (XRD). Scanning Electron Microscopy (SEM) was used to find the nano nature of the crystallinity. In addition, the optical properties were measured employing room temperature Photoluminescence (PL) spectroscopy. XRD spectra confirmed the mixed amorphous and crystalline nature of the glass. SEM studies revealed the nanocrystal glass morphology associated with the existence of crystalline phase. The influence of heat treatment process on the luminescence properties was performed in detail. The observed emission peaks for the luminescence such as ⁵D0 → ⁷D0, ⁵D0 → ⁷F1, ⁵D0 → ⁷F2, ⁵D0 → ⁷F3 and ⁵D0 → ⁷F4 were found to be located at around the wavelength of 568 nm, 600 nm, 628 nm, 664 nm and 712 nm respectively. The enhancement of Eu³⁺ luminescence especially for the highest emission intensity, ⁵D0 → ⁷ F2 transition lies in the red region as compared to the precursor glass. Our findings may provide some useful information towards the development of functional glasses with controlled structural and optical properties.