Bonding mechanism and relaxation energy of SrBi2B2O9 (B = Ta, Nb): First-principles study

作者：Shu, H B; Sun, L Z^*; Zhong, X L; Wang, J B; Zhou, Y C

来源：Journal of Physics and Chemistry of Solids, 2009, 70(3-4): 707-712.

DOI：10.1016/j.jpcs.2009.02.012

• Inorganic compounds
• Ab initio calculations
• Electronic structure
• Ferroelectricity

Using first-principles calculations, we have studied the electronic structures, the relaxation energy and the bonding mechanism of SrBi2B2O9 (B = Ta, Nb). Unlike the case of prototype perovskites, the covalent bonding between cations and oxygen of SrBi2B2O9 (B = Ta, Nb) does not directly stabilize their ferroelectric phase through reducing their total energy. Whereas, the ferroelectric stability of SBN and SBT is determined by a large relaxation energy derived from a larger distortion along with their phase transition. The origin of the spontaneous polarization of the materials is also briefly discussed in our present work.

• 出版日期2009-4
• 单位湘潭大学