High temperature vaporization and Raoultrsquo;shyphen;law studies with243Am metal

摘要

The vapor pressure of high purity243Am metal has been measured over the temperature range 1200–1600 K, using combined target and mass spectrometric Knudsen effusion techniques. This work was performed to extend data into the liquid phase, and to compare results with earlier241Am experiments. Second‐law and third‐law heats of vaporization are in close agreement with the earlier work, and no isotope effect was found. An additional study of the vaporization of243Am from a liquid La host was made to explore solubility relationships and activities for systems with similar electronic properties. Lanthanum was found to be a nearly ideal solvent, giving the correct heat of vaporization for Am, and activity coefficients slowly changing with temperature, representative of the effects of a small heat of mixing.