TY - JOUR
T1 - Ab initio determination of total-energy surfaces for distortions of ferroelectric perovskite oxides
AU - Hashimoto, Takatoshi
AU - Nishimatsu, Takeshi
AU - Mizuseki, Hiroshi
AU - Kawazoe, Yoshiyuki
AU - Sasaki, Atsushi
AU - Ikeda, Yoshiaki
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2004/9
Y1 - 2004/9
N2 - We established a new ab initio structure optimization technique of determining the valley line on a total-energy surface accurately for the zone-center distortions of ferroelectric perovskite oxides, and applied this technique to the analysis of barium titanate (BaTiO3), lead titanate (PbTiO3), and lead zirconate (PbZrO3). The proposed technique is an improvement over King-Smith and Vanderbilt's scheme [Phys. Rev. B 49 (1994) 5828] of evaluating total energy as a function of the amplitude of atomic displacements. The results of numerical calculations show that total energy can be expressed as a fourth-order function of the amplitude of atomic displacements in BaTiO3 but not in PbTiO3 and PbZrO 3. These results will provide some hints about the reason Pb(Zr xTi1-x)O3(PZT) has a large piezoelectric response. These results are due to the fact that our structure optimization technique automatically takes account of the higher-order coupling between atomic displacements and strains, and not only the atomic displacements of the ΓO15 soft mode but also that of the hard modes.
AB - We established a new ab initio structure optimization technique of determining the valley line on a total-energy surface accurately for the zone-center distortions of ferroelectric perovskite oxides, and applied this technique to the analysis of barium titanate (BaTiO3), lead titanate (PbTiO3), and lead zirconate (PbZrO3). The proposed technique is an improvement over King-Smith and Vanderbilt's scheme [Phys. Rev. B 49 (1994) 5828] of evaluating total energy as a function of the amplitude of atomic displacements. The results of numerical calculations show that total energy can be expressed as a fourth-order function of the amplitude of atomic displacements in BaTiO3 but not in PbTiO3 and PbZrO 3. These results will provide some hints about the reason Pb(Zr xTi1-x)O3(PZT) has a large piezoelectric response. These results are due to the fact that our structure optimization technique automatically takes account of the higher-order coupling between atomic displacements and strains, and not only the atomic displacements of the ΓO15 soft mode but also that of the hard modes.
KW - First-principles calculation
KW - Lagrange multiplier
KW - Lead-free
KW - Potential surface
KW - Valley line
UR - http://www.scopus.com/inward/record.url?scp=10444282795&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=10444282795&partnerID=8YFLogxK
U2 - 10.1143/JJAP.43.6785
DO - 10.1143/JJAP.43.6785
M3 - Article
AN - SCOPUS:10444282795
VL - 43
SP - 6785
EP - 6792
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - 9 B
ER -