Quantum Effect on SrRuO₃/BaTiO3/SrRuO₃ Ferroelectric Ultrathin Film Capacitor

Abstract

We have carried out a detailed investigation on the quantum effect on SrRuO₃/BaTiO3/SrRuO₃ ferroelectric ultrathin film capacitors fully strained with a SrTiO₃ substrate. We employ the transverse field Ising model, taking into account the incomplete charge compensation of the realistic SrRuO₃ electrode and the misfit strain imposed by the SrTiO₃ substrate in the Hamiltonian, to quantitatively explain the experimental observation in the literature. It is found that quantum mechanism under the influence of the incomplete charge compensation of the electrode plays an important role in determining the ferroelectric properties of BaTiO₃ ultrathin films between two metallic electrodes.

Keywords:

• Ferroelectric ultrathin film
• spontaneous polarization
• dielectric susceptibility

PACS numbers:

• 77.84.Dy, 77.80.-e, and 77.55.+f

Acknowledgments

This work was supported by the Natural Science Foundation of China under contract No. 10747114 and Shanghai Educational Development Foundation under contract No. 2007CG43.