Nonlinear susceptibility of SrTiO₃:Ca

Abstract

The nonlinear dielectric response of Sr_1−xCa_xTiO₃(SCT) is described in terms of various quantum model approaches. Field and temperature dependencies and the corresponding scaling properties are approached both by simulations within the framework of a heterogeneous transverse Ising model (TIM) and by analytical solutions within the framework of TIM and a coupled anharmonic quantum oscillator model. Alternatively, we propose an empirical approach, which models both phonon- and random field-induced clustering processes.

Key Words:

• Keywords: Quantum paraelectric
• transverse Ising model
• polar impurities