Solid-state synthesis of the Zn2SiO4:Mn phosphor: Sequence of phase formation, localization and charge state of Mn ions in the intermediate and final reaction products

Abstract

The phase and structure formation of the Zn2SiO4:Mn phosphor during solid-state synthesis in air from ZnO, SiO2, and Mn2O3 was studied by differential thermal, thermogravimetric, X-ray phase diffraction, and luminescent analyses. It has been shown that the first product of their interaction is a solid solution with the spinel structure (Zn1-хMn2+х)Mn3+2O4 (700°С); with an increase in temperature, ZnMn3+2O4 heterolite is formed. When heated to 900°С, willemite Zn2SiO4 appears along with heterolite. At higher temperature, the interaction of ZnMn3+2O4 with SiO2 leads to the formation of Zn2SiO4:Mn with an impurity of rhodonite Mn2+SiO3. A further increase in temperature activates the interaction of willemite, heterolite, rhodonite, silicon and zinc oxides. At about 1250 °C, this heterophase mixture forms the final single-phase product - the Zn2SiO4:Mn phosphor.