Lattice dynamics of strontium oxide

Abstract

The phonon dispersion relations of SrO at 300\ifmmode^\circ\else\textdegree\fi{}K for the $[\ensuremath{\zeta}00]$, $[\ensuremath{\zeta}\ensuremath{\zeta}0]$, and $[\ensuremath{\zeta}\ensuremath{\zeta}\ensuremath{\zeta}]$ directions of propagation have been measured using inelastic neutron scattering. A shell model with seven parameters gives a good over-all description of the phonon dispersion relations. The phonon frequency distribution calculated with this model yields a temperature dependence of the characteristic Debye temperature which is in satisfactory agreement with results derived from specific-heat measurements. The second-order Raman spectrum of SrO is discussed on the basis of the neutron data and a calculated two-phonon density of states.