Nd3+doped- SiO2–KLaF4 oxyfluoride glass-ceramics prepared by sol-gel

Abstract

Neodymium (Nd3+) doped SiO2–KLaF4 oxyfluoride glass-ceramic (GCs) containing 10 mol% and 20 mol% of KLaF4 nanocrystals (NCs) were prepared for the first time by sol-gel and sintered at 550 °C. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were used to analyze the evolution of the xerogel during the heat treatment, high-resolution transmission electron microscopy (HRTEM) was employed to study the formation and distribution of NCs in the silica matrix. The decomposition of trifluoroacetic acid (TFA) and the crystallization of fluoride nanocrystals were also confirmed. The presence of α-KLaF4 and β-KLaF4 crystalline phases with maximum crystal sizes of 24 nm and 17 nm respectively were clearly observed after heat treatment at 550 °C for 1 min. Site-selective emission and excitation spectra confirmed the incorporation of Nd3+ ions in both crystalline phaseswith emission of Nd3+ most predominant in the β-KLaF4 NCs.