Preparation of PbGeO3 by the oxidation of Pb–Ge melts and its properties

Resumo

This paper presents experimental data on the oxidation kinetics of a liquid 65 at % Pb + 35 at % Ge alloy in air. Lead metagermanate, PbGeO₃, in a glassy state has been prepared by high-temperature oxidation of the melt at 1273 K. Interaction of molten PbGeO₃ with crucible materials (SnO₂, Au, Pd, and Pt) has been studied by the sessile drop method. Liquid lead germanate has been shown to be highly reactive with substrates from these materials. The heat capacity of the glassy lead metagermanate obtained has been determined by differential scanning calorimetry in the temperature range 300–800 K. In the range 330–630 K, the C_p(T) data for glassy PbGeO₃ can be represented using the Maier–Kelley equation. Above 630 K, there is a characteristic peak due to glass crystallization processes.