Question

For the perovskite structure type, sketch example LA (longitudinal acoustic), TA (transverse acoustic), LO (longitudinal optical) and TO (transverse optical) atomic vibrational modes at both k (0,0,0) and k=(0,0,τ/a). (g) 18 m

Answer 1

"In higher dimension, the deformation u^rightarrow & x^rightarrow wave vector x^rightarrow, Depending on angle b/w u^rightarrow (Longitudinal & Transverse mode) Longitudinal mode rightarrow u^rightarrow