Spectroscopic evaluation of the specific heats of potassium bromide
The spectrum of free vibrations of the structure of potassium bromide is determined spectroscopically from the scattering within the crystal of the resonance radiation of the mercury arc. The modes are recorded with doubled frequency shifts. The identification of these shifts as arising from the various modes of vibration is made on the basis of the frequencies as computeda priori from the dynamic theory and from a consideration of their observed spectral intensities. From these spectral frequencies, the specific heat of the crystal can be evaluated as a function of the temperature. When the variations with temperature of the vibration frequencies are taken into account, a satisfactory agreement emerges between the theoretically computed and experimentally observed specific heat data.