Coupling of Optic and Acoustic Modes of Vibration in Crystals

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. In the present case of a diatomic lattice9 the secular equation is a 2 x 2 determinant9 having two solutions (qqeps) for each of the EN values of k lying in the first Brillouin zone; these two solutions correspond t...