Phase transition due to nonlinear resonance of lattice
Aleksandrov K.S. , Aleksandrova I.P., Zaslavskii G.M., Sorokin A.V. , Shabanov V.F.
Raman spectroscopy in the polarized phase was used to observe, in a number of ferroelectrics of the order-disorder type, two low-frequency oscillations with strong temperature dependence of the frequencies as T—>TC. This dependence is regarded as a result of nonlinear resonant interaction of two lattice vibrations near the Curie point, and a model is proposed for the phase transition due to this resonance.