Low-temperature phase in Li_xK_1-xTaO₃

Abstract

Abstract Lithium, substituting K in the perovskite KTaO3, creates a local electric dipole due to its off-center position with respect to the cubic site. Inter-action between these moments leads to a low-temperature phase which is still controversial, since it reveals signatures of both glass-like and long range order behavior. This work covers recent theoretical investigations of the effective Li-Li interaction and the nature of the low-temperature phase in Li x K1-x TaO3, performed in the framework of a non-linear shell model.