Crystallochemical and Voltammetric Characterization of the Zn2 – 2хMn2хSiO4 Luminophor

The region of homogeneity in a solid solution of the nominal composition Zn 2 – 2 x Mn 2 x SiO 4 ( х ≤ 0.21 ± 0.01) is determined. A comparison of the values of the pycnometric and X-ray densities for the compositions with x ≥ 0.13 ± 0.01 indicates the coexistence of manganese ions in two charge states: Mn 2+ and Mn 3+ . It is established voltammetrically that all of the manganese ions in Zn 1.8 Mn 0.2 SiO 4 are divalent, and the concentrations of Mn 2+ and Mn 3+ ions in Zn 1.6 Mn 0.4 SiO 4 are comparable. The oxidation of some Mn 2+ ions results in the concentration quenching of luminescence in Zn 2 – 2 x Mn 2 x SiO 4 solid solutions at х > 0.13 ± 0.01.