Ionic polarizability of conductive metal oxides and critical thickness for ferroelectricity in BaTiO3
We report a first-principles investigation of ultrathin BaTiO3 films with SrRuO3 electrodes. We find that the ionic relaxations in the metal-oxide electrode play a crucial role in stabilizing the ferroelectric phase. Comparison with frozen-phonon calculations shows that the degree of softness of the SrRuO3 lattice has an essential impact on the screening of ferroelectric polarization in BaTiO3. The critical thickness for ferroelectricity in BaTiO3 is found to be 1.2 nm. The results of our calculations provide a possible explanation for the beneficial impact of oxide electrodes on the switching and dielectric properties of ferroelectric capacitors.
Gerra, G Swiss Fed Inst Technol, Ceram Lab, CH-1015 Lausanne, Switzerland Swiss Fed Inst Technol, Ceram Lab, CH-1015 Lausanne, Switzerland Polish Acad Sci, Inst Nucl Phys, PL-31342 Krakow, Poland
Cited References Count:28
Record created on 2006-08-21, modified on 2016-08-08