Elastic Constants of RbF from 300 to 4.2 K

Abstract

The adiabatic elastic constants have been measured in single crystals of rubidium fluoride over the temperature range of 300 to 4.2 K to investigate a discrepancy with neutron scattering data. The values of the elastic constants at 0 K, extrapolated from 4.2 K, are $C_{11}=6.527\mathrm{}$, $C_{44}=0.952\mathrm{}$, and $C_{12}=1.255\mathrm{}$ in units of ${10}^{11}$ ${\mathrm{d}\mathrm{y}\mathrm{n}/\mathrm{c}\mathrm{m}}^2$. The Debye characteristic temperature at 0 K (${\Theta }_D$) as calculated from the elastic constants is ${\Theta }_D=221.0\mathrm{}$ K. A summary of Debye temperature values calculated from elastic constant data at 0 K is presented for all previously measured face-centered-cubic alkali halides.