Direct observation of covalency between O and disordered Pb in cubic PbZrO3
Direct observation of covalency between O and disordered Pb in cubic PbZrO3
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DOI：
10.1143/jpsj.71.2353
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发表时间：
2002-10-01
影响因子：
1.7
通讯作者：
Sakata, M
中科院分区：
文献类型：
--
作者：
Aoyagi, S;Kuroiwa, Y;Sakata, M
在立方相PbZrO_3中，通过对高能X射线粉末衍射数据的分析，首次发现了Pb在12个位置上向邻近O的无序.在电荷密度分布中，Pb-O键的共价性也被揭示出来，证明了立方PbZrO 3中O与无序Pb之间存在电子杂化。在以前研究的立方PbTiO_3结构中没有发现PbZrO_3的这些结构特征[Y. Kuroiwa等人：物理修订信函87（2001）217601]，其经历铁电相变。这可能是理解为什么PbTiO_3和PbZrO_3分别显示铁电和反铁电相变的线索。
In cubic PbZrO3, which undergoes an anti ferroelectric phase transition, the distinct disorder of Pb at twelve sites toward the neighboring O is detected for the first time by analyzing high-energy X-ray powder diffraction data. In the charge density distributions, the covalent nature of the Pb-O bond is also revealed, which proves the existence of electron hybridization between O and disordered Pb in cubic PbZrO3. None of these structural characteristics of PbZrO3 were found in the previously studied cubic PbTiO3 structure [Y. Kuroiwa et al.: Phys. Rev. Lett. 87 (2001) 217601], which undergoes a ferroelectric phase transition. This may be a clue to understanding why PbTiO3 and PbZrO3 respectively show ferroelectric and antiferroelectric phase transitions.