@article{10902/4181,
year = {2010},
month = {7},
url = {http://hdl.handle.net/10902/4181},
abstract = {We report a first-principles study of (BaTiO3)m/(BaO)n superlattices for a wide range of periodicities m/n. We show that such a system develops a polar zone-center instability for sufficiently large m/n ratio, which can be understood, at least qualitatively, from a simple electrostatic model and should lead to a ferroelectric ground state. However, the analysis of the phonon-dispersion curves also points out the appearance of stronger antiferroelectric instabilities at the zone boundaries around m=4, before the critical ratio for ferroelectricity is reached and which still dominate beyond it. The dominant character of the antiferroelectric instability is explained from the depolarizing field which hardens the ferroelectric mode. This analysis allows us to predict that, (BaTiO3)m/(BaO)n superlattices should present an antiferroelectric ground state for m larger than 4, which should smoothly evolve to a multidomain structure for increasing m values and only become ferroelectric for large m.},
organization = {This work was supported by the European Project No. CP-FP 228989-2 OxIDes of the Seventh Framework Program, the European Multifunctional Institute, and the Interuniversity Attraction Poles Program (P6/42)—Belgian State—Belgian Science Policy. J.J. acknowledges financial support of the Spanish Ministry of Science and Innovation through the MICINN under Grant No. FIS2009-12721-C04-02. E.B. also acknowledges FRS-FNRS Belgium.},
publisher = {American Physical Society},
publisher = {Physical review. B, Condensed matter and materials physics, 2010, 82(4), 045426},
title = {First-principles study of competing ferroelectric and antiferroelectric instabilities in BaTiO3/BaO superlattices},
author = {Bousquet, Eric and Junquera Quintana, Francisco Javier and Ghosez, Philippe},
}