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Orbital Hybridization of the Ferroelectric Rb2Cd2 (SO4)3: Origin of Domain Walls |
| DUAN Yi-Feng;YI Lin |
| Department of Physics and State Key Laboratory of Laser Technology, Huazhong University of Science and Technology, Wuhan 430074 |
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| Cite this article: |
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DUAN Yi-Feng, YI Lin 2005 Chin. Phys. Lett. 22 439-441 |
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Abstract We perform first-principle calculations for the study of the orthorhombic Rb2Cd2 (SO4)3 structure. Electronic energy bands, total and partial densities of states are reported and analysed. It is found that oxygen atomic 2p electrons strongly hybridize with Rb/or Cd 4d and S 2p states, resulting in two-type ionic groups with weak couplings. It is shown that macroscopic domain walls originate from such weak-coupling ionic groups, arising at the cell boundaries. The asymmetric cation bonds (Rb--O and Cd--O) and the subsequent rotations of the SO4 tetrahedra can lead to the driving force of the ferroelectric behaviour. The predicted pyroelectric current effects are observed experimentally in the ferroelectric phase.
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| Keywords:
71.20.-b
77.80.-e
71.15.Ap
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Published: 01 February 2005
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| PACS: |
71.20.-b
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(Electron density of states and band structure of crystalline solids)
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77.80.-e
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(Ferroelectricity and antiferroelectricity)
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71.15.Ap
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(Basis sets (LCAO, plane-wave, APW, etc.) and related methodology (scattering methods, ASA, linearized methods, etc.))
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