Metal halide vapour complexes: vapour transport and lamp experiments

Stable vapor complexes of the type ABX sub(m+n) can sometimes increase the vapor concentration of a low volatility salt above the liquid pool. If the equilibrium concentration of A and/or B, in all their molecular forms above the binary melt AX sub(m)/BX sub(n) exceed their values above their respective pure salts enhancement (F > 1) has occurred. Mass spectrometric data suggests that such enhancement may occur in two dissimilar systems NaCl/PbCl sub(2) (F sub(Na) > 1) and NaCl/DyCl sub(3) (F sub(Dy) > 1). Vapor transport and electrical discharge lamp experiments have been used to test this prediction by direct measurement of the enhancement and the results are reported here.