Emission spectra of XeBr, XeCl, XeF, and KrF

Abstract

The emission spectra of XeBr, XeCl, XeF, and KrF at high pressure are reported and discussed. The spectra were obtained by observing spontaneous emission from electron beam excited mixtures of argon containing lesser amounts of xenon with the halogens or krypton with fluorine. The emitting state in these species is best described as an ionic species Xe⁺X⁻ or Kr⁺F⁻. The wavelengths of these emission bands are in good agreement with a theoretical model in which the ionic binding energy of the noble gas halide ion pair is roughly equal to that of the nearest alkali halide. Our high pressure spectra imply that the lowest potential energy curve for XeF is bound.