| Autor: |
Hiromu Miyazawa, Ishii, Fumiyuki, Natori, Eiji, Shimoda, Tatsuya, Oguchi, Tamio |
| Předmět: |
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| Zdroj: |
Ferroelectrics; 2004, Vol. 301 Issue 1, p49-53, 5p, 1 Diagram, 4 Graphs |
| Abstrakt: |
We have studied the nature of the covalent bond between Pb 6p and O 2p orbitals in perovskites based on first-principles calculations with Berry phase theory. We compared the electric polarization and Young's modulus between PbTiO3 and BaTiO3. We found that PbTiO3 has higher electric polarization and softness than BaTiO3 because of the cooperation mode of both Ti-O(2) and Pb-O(1) covalent bonds. We propose that in the structural phase transition the system with the lower symmetry avoids ion repulsion through the additional degree of freedom available from atom displacement. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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