TY - EJOU AU - Uludoğan, Mustafa AU - Guarin, D. Paula AU - Gomez, Zully E. AU - Cagin, Tahir AU - III, William A. Goddard TI - DFT Studies on Ferroelectric Ceramics and Their Alloys: BaTiO3, PbTiO3, SrTiO3, AgNbO3, AgTaO3, PbxBa1-xTiO3 and SrxBa1-xTiO3 T2 - Computer Modeling in Engineering \& Sciences PY - 2008 VL - 24 IS - 2&3 SN - 1526-1506 AB - Aiming at a presentation of the utility of the state of art of first-principles methods (PBE flavor of Density Functional Theory, DFT) in the area of materials science and engineering, we present our studies of the equation of state and ferroelectric-paraelectricphase transition in several ferroelectric systems, including BaTiO3, PbTiO3, SrTiO3, AgNbO3, PbxBa1-xTiO3 and SrxBa1-xTiO3. We also report the Born effective charges, optical dielectric constant, and phonon dispersion relation properties from Density Functional Perturbation Theory. Computed results are compared with other theoretical results (which were mostly on BaTiO3, PbTiO3, cubic SrTiO3 using various approaches, as well as experiments. The studies on AgNbO3 and alloys are the first calculations to the best of our knowledge. The predictions obtained by DFT studies presented are in good agreement with the experimental results. KW - DO - 10.3970/cmes.2008.024.215