The Thermal Decomposition of Silver(I) Oxide

Abstract

The thermal decomposition of precipitated silver(I) oxide in a vacuum has been studied over the range 100-350 °C. Three regions are identified : in the fist, 100-200 °C, the activation energy is 30 kcal, 5 per cent. of the total oxygen is evolved, and the lattice parameter increases to a limiting value ; in the second, 200-300 °C, the activation energy is 50 kcal, and a further 1-2 per cent. oxygen is evolved; in the third, above 300 °C, metallic silver crystallizes, the oxide lattice contracts to a constant value, and the activation energy becomes 36 kcal. The activation energies in the three regions are interpreted as being associated, respectively, with (i) the diffusion of silver into the oxide lattice, (ii) the formation of aggregates of silver " atoms " not conforming to the normal silver lattice in an oxide lattice saturated with silver, and (iii) the reaction at the interface between metallic silver and the oxide.