Upconversion luminescence in transparent oxyfluoride glass ceramics containing hexagonal NaErF4

Abstract

Transparent oxyfluoride glass ceramics containing hexagonal NaErF4 nanocrystals were synthesized by a heat treatment of a precursor glass obtained by the melt quenching technique. Combined X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis revealed the formation of single phase nanocrystals in the glass ceramics. The enhancement of intensity and spectral change of upconversion luminescence (UCL) confirmed the presence of Er3+ ions in the crystalline phase of the glass ceramics. Dominant energy transfer processes were identified using the rate equation formalism. Time-resolved site-selective spectroscopy studies at low temperatures were employed to elucidate the local structure of Er3+ ions in the glass ceramics and microcrystalline NaErF4. The origin of multi-site formation in hexagonal NaErF4 lattice is discussed.----/ / /---- This is the preprint of the following article: Guna Krieke; Andris Antuzevics, Maris Springis, Uldis Rogulis, Upconversion luminescence in transparent oxyfluoride glass ceramics containing hexagonal NaErF4, Journal of Alloys and Compounds Volume 798 (2019), which has been published at https://www.sciencedirect.com/science/article/abs/pii/S0925346717304731. This article may be used for non-commercial purposes in accordance with Elsevier Terms and Conditions for Sharing and Self-Archiving. © 2019. This work is licensed under a CC BY-NC-ND 4.0 license.