Investigation for the Thermodynamic Polarization Degradation of the BaTiO3 Crystal Thin Films

Abstract

According to the latest development of memory, it is found that the motion of ferroelectric domain wall is very important for the high-density non-volatile devices of ferroelectric materials. This paper mainly studies the microstructure of barium titanate (BaTiO3) crystal films with the molecular dynamics of crystal domain motion and then models the polarization degradation with the conservation of the nucleation energy-focusing and free energy thermodynamic processes in the crystalline domains. First, by the means of XRD diffractometer and JADE software, the crystal axis orientation of BaTiO3 thin film is analysed, and then the crystal axis orientation is determined by referring the published measurement results. Further, for the ferroelectric crystal BaTiO3 thin film, the thermodynamic process is studied and the temperature dependences of the polarization ratio with respect to the spontaneous polarization is modelled. Numerical simulations have shown the much higher temperature dependence on the nucleation energy than on the free energy in a domain wall system, leading to the possibility to reach a high polarization ratio with the optimal deposition conditions to control the local energy and the nucleation energy cost of crystalline domains.