Luminescence properties and thermal stability of a red phosphor ZnSiF6·6H2O:Mn4+ synthesized by the one-step hydrothermal method

A red phosphor composed of Mn4+ embedded in host lattice of ZnSiF6·6H2O has been prepared by a one-step hydrothermal method. The host lattice ZnSiF6·6H2O is obtained from ZnF, SiO2 and HF. The luminescence center of Mn4+ is formed by incomplete reduction of KMnO4 with HF. The composition and crystal structure have been determined with measurements of XRD, EDS and infrared spectra. The thermal stability has been investigated by TG-DSC. The H2O molecules in the compound are not combined crystal water but structural water that coordinate Zn2+. The luminescence properties of phosphor ZnSiF6·6H2O:Mn4+ at 78 K and 298 K have been investigated. Luminescence quenches at a temperature higher than 200 °C mainly which is due to the decomposition of crystal structure.