Electronic structure studies of the differences in ferroelectric behavior of batio₃and PbTiO₃

Ab initio statistical mechanics of the ferroelectric phase transition inPbTiO3

“…6. This is consistent both with previous first principles calculations 2 Considering that the atomic displacements in P bT iO 3 are relatively large, the presence of such anharmonicity is not surprising. However, as discussed above, the ground state of the model is very similar to the experimental ground state and the small loss of accuracy is more than compensated for by the gain in simplicity.…”

“…With advances in algorithms and computational capabilities, the challenge of achieving the high accuracy necessary for studying these distortions has been largely met, and ground state distortions well reproduced for a wide range of perovskite-structure oxides [2][3][4] . However, for ab initio molecular dynamics or Monte Carlo, the system sizes required for the study of finite-temperature structural transitions are still completely impractical.…”

Continuum thermodynamics of ferroelectric domain evolution: Theory, finite element implementation, and application to domain wall pinning

“…The theory falls into the class of phase-field or diffuse-interface modeling approaches (Cao and Cross, 1991;Nambu and Sagala, 1994;Hu and Chen, 1997;Cao, 2000, 2001;Li et al, 2001Li et al, , 2002and Zhang and Bhattacharya, 2005a,b), which has the potential to bridge atomistic calculations (Cohen and Krakauer, 1992;Meyer and Vanderbilt, 2002) and the larger scale phenomenological modeling approaches. In a departure from previous derivations of the phase-field equations, a set of micro-forces and governing balance laws are postulated and applied within the second law of thermodynamics to identify the appropriate material constitutive relationships, Gurtin, 1993, 1994;Gurtin, 1996).…”

Modification of Local Electronic Structures Due to Phase Transition in Perovskite-Type Oxides, SrBO<SUB>3</SUB> (B=Zr, Ru, Hf)

“…The structural stability was treated following the total energy calculations. 6,7) Also, the transition temperature was calculated using the molecular dynamics and the Monte-Carlo simulations. 8,9) In this study, the electronic structures of SrZrO 3 , SrRuO 3 and SrHfO 3 are simulated by the DV-X molecular orbital method in order to account for the characteristic features for the tilting-type phase transition in view of the nature of the chemical bond between ions.…”