A linear diatomic lattice of lattice constant a with masses M and m (…

Question

A linear diatomic lattice of lattice constant a with masses M and m (M > m) are coupled by a force constant C. The dispersion relation is given by

ω^{2} = C (\frac{M + m}{M m}) \pm [C^{2} (\frac{m + m}{M m})^{2} - \frac{4 C ^{2}}{M m} sin^{2} \frac{k a}{2}]^{\frac{1}{2}}

Which one of the following statements is incorrect?

Accepted Answer

Option C. The dispersion of frequency in the optical branch is smaller than that in the acoustic branch. Answer & Solution Answer: Option C No explanation is given for this question Let's Discuss on Board

A linear diatomic lattice of lattice constant a with masses M and m (M > m) are coupled by a force constant C. The dispersion relation is given by ^2 = C ( M + mMm ) [ C^2 ( m + mMm )^2 - 4C^2Mm ^2 ka2 ]^1/2 Which one of the following statements is incorrect?

Solution