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[摘要]：Weak-relaxor behaviour was observed in K(1-x)Bi(x)Nb(1-x)YbxO(3) ceramics with x = 0.20 and x 0.30. According to x-ray diffraction analysis, the crystal structure of these ceramics can be described by the cubic centrosymmetric Pm-(3) over barm space group; however Raman spectroscopy reveals both the occurrence of local lattice distortions and the disruption of the long-range ferroelectric order. The local lattice strain caused by the larger Yb3+ combined with the presence of Bi3+, which lone-pair of electrons induces further local distortions, gives rise to polar nanoregions (PNRs). Nevertheless, the interaction between the PNRs appears weak and proper relaxor behaviour does not develop. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3660255] |
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