摘要
Aurivillius ferroelectrics K 0.25Na 0.25La 0.5Bi 2Nb 2O 9 (KNBN-La) and K 0.25Na 0.25Bi 2.5Nb 2O 9 (KNBN-Bi) were prepared by using solid-state reaction process. Rietveld refinements for the KNBN-La and KNBN-Bi were carried out by using powder X-ray diffraction at room temperature and they were confirmed to be two-layer Aurivillius oxides with orthorhombic space group A2 1am. The lattice parameters are a = 5.50468(10) Å, b = 5.49217(10) Å, and c = 25.05108(35) Å for KNBN-La and a = 5.48867(6) Å, b = 5.47895(6) Å, and c = 25.10591(25) Å for KNBN-Bi. Lanthanum (La 3+) substitution for bismuth (Bi 3+) led to an enhancement in relaxation behavior for the KNBN-La ceramics, with a ferroelectric to paraelectric phase transition temperature (T c) of about 360 °C. The KNBN-La ceramics had a high remnant polarization (P r) of 13.6 μC cm -2 and a field-induced strain of up to 0.031%. Particularly, the decrease in P r for the KNBN-La ceramics after 10 8 cumulative switching cycles was only 6%.
源语言 | 英语 |
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页(从-至) | 11046-11054 |
页数 | 9 |
期刊 | Dalton Transactions |
卷 | 41 |
期 | 36 |
DOI | |
出版状态 | 已出版 - 28 9月 2012 |