First-principles investigation of phenomenological properties in Ba1-xSrxTiO3

First-principles calculations were used to evaluate the coefficients of the phenomenological equation for perovskite compounds of Ba1-xSrxTiO3 up to the eighth order. The second- and fourth-order coefficients for the cubic structure's phenomenological equation agreed with the previously reported values [King-Smith and Vanderbilt, Phys. Rev. B 49, 5828 (1994), Nishimatsu et al., Phys. Rev. B 82, 134106 (2010)]. The coefficients of the phenomenological equation, up to the eighth order, were used to estimate the polarization P-3 and the piezoelectric constant d(33). While the P-3 values estimated in this study and those evaluated by first-principles calculation matched, the d(33) values differed significantly depending on the estimation method. The difference is likely due to the estimated relative dielectric susceptibility coefficient eta(33). When eta(33) is estimated accurately, the properties of perovskite oxides can probably be predicted easily. (C) 2014 The Japan Society of Applied Physics