Entropies, Heats of Sublimation, and Dissociation Energies of the Cesium Halides

Abstract

The vapor pressures of the crystalline cesium halides have been measured in the 700–900°K temperature range. The salt vapor effusing from a Knudsen effusion cell was accurately collimated into a molecular beam with a well-defined cross-sectional area. Beam intensities were determined from the positive ion currents produced by dissociation of the halide and ionization to Cs+ on a tungsten surface at 1700°K. From the experimental vapor pressures and heats of sublimation, the crystal entropies, dissociation energies, and heats of sublimation at 298°K were computed using available spectroscopic and thermal data.