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Effects of Li Substitution on the Structure and Ferroelectricity of (Na,K)NbO 3
Author(s) -
Sun Xueyi,
Deng Jinxia,
Chen Jun,
Sun Ce,
Xing Xianran
Publication year - 2009
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2009.03303.x
Subject(s) - natural bond orbital , orthorhombic crystal system , raman spectroscopy , tetragonal crystal system , ferroelectricity , rietveld refinement , phase transition , materials science , crystallography , chemistry , analytical chemistry (journal) , crystal structure , condensed matter physics , dielectric , computational chemistry , density functional theory , physics , optics , optoelectronics , chromatography
The structures of (1− x )(K 0.5 Na 0.5 )NbO 3 – x LiNbO 3 were investigated by the X‐ray Rietveld method at room temperature. It is surprising to find that the spontaneous polarization of orthorhombic phase reaches at the lowest value and the spontaneous polarization of tetragonal phase reaches at highest value at x =0.06. The lattice parameter of (K 0.47 Na 0.47 )NbO 3 –0.06LiNbO 3 , which was refined by using two phase model, reasonably described the structure change of the (1 x )(K 0.5 Na 0.5 )NbO 3 – x LiNbO 3 . The temperature dependence of Raman spectroscopy study of the phase transition of (K 0.47 Na 0.47 )NbO 3 –0.06LiNbO 3 showed that the increasing of temperature introduced a local disorder even above T c . The degree of cation ordering determines the electrical properties of the ceramics.