R. Penzhorn, H. Ihle, P. Schuster
Sep 1, 1994
Citations
0
Influential Citations
7
Citations
Journal
Journal of Nuclear Materials
Abstract
The formation of an oxygen-deficient layer at the surface of lithium orthosilicate by reaction with hydrogen is confirmed by the following findings: i) formation of hydrogen by reaction with water vapor, ii) uptake of oxygen, and iii) increase in lithium partial pressure and decrease in oxygen partial pressure relative to conditions in the absence of hydrogen according to p(Li)4p(O2)−1. The partial pressures of D2, D2O, Li, and LiOD in the saturated vaport over Li4SiO4 were measured as function of temperature under steady state conditions reached in the late phase of long-term experiments. The employed temperature range, e.g. 945–1173 K, is in or close to the region of interest to blanket technology. From the data on the temperature dependence of the ratio p(D2O)/p(D2) an enthalpy of reaction for the formation of the reduced layer on lithium orthosilicate by reduction with deuterium of ΔH°1059K = (37.0±0.2) kJ/mol is calculated.