Determination of the Inelastic Scattering at Bragg Reflections of KCl by Means of the Mössbauer Effect: Contribution of Multiphonon-Scattering Terms

The scattering intensities of the 14.4-KeV $\gamma$ rays from a ${\mathrm{Co}}^{57}$ source were measured at the {800} and {1000} reflections of KCl crystals in the temperature interval 80-900°K. The elastic and inelastic components of the scattered intensities were separated by means of nuclear-resonance absorption. The temperature dependence of the inelastic intensities was in satisfactory agreement with the calculated one, when the contributions of multiphonon scattering terms were included in the evaluation of the thermal diffuse-scattering intensity. The Debye temperature $\Theta =23\mathrm{}0\pm 4°$K which was derived from the temperature dependence of the elastic intensities was in good agreement with the value found in the literature.