VARIATION OF F-CENTER CONCENTRATION IN DILUTE K-KCL SOLUTION - COMPARISON OF AN OPTICAL STUDY WITH THERMODYNAMIC PREDICTION

We have measured the concentration of liquid F-centers by optical absorption in KxKCl1-x solutions at 790-degrees-C over a wide range of compositions up to a metal mole fraction x = 0.01. The composition has been accurately controlled by coulometric titration in situ. These results are compared with the predictions of the F-center concentration as determined from metal activity measurements using a thermodynamic electron defect model. Good agreement is found between these separate data sets for a variation of composition by two orders of magnitude.