Ferroelectric Phase Transitions in New Aurivillius Oxides : Bi_<2+2x>Sr_<1-2x>Nb_<2-x>Sc_xO_9
Ferroelectric Phase Transitions in New Aurivillius Oxides : Bi_<2+2x>Sr_<1-2x>Nb_<2-x>Sc_xO_9
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新型 Aurivilius 氧化物中的铁电相变：Bi_<2 2x>Sr_<1-2x>Nb_<2-x>Sc_xO_9
DOI：
10.1039/c1jm11297j
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发表时间：
2011
影响因子：
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通讯作者：
Thathan Sivakumar and Mitsuru Itoh
中科院分区：
文献类型：
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作者：
L.Aleksandrov;T.Komatsu;R.Iordanova;Y.Dimitriev;村上由紀子,伊香賀俊治,堀進悟,鈴木昌,三宅康史;Thathan Sivakumar and Mitsuru Itoh
采用标准固相法合成了一系列B位含Sc 3+的铁电Aurivillius氧化物Bi 2 + 2xSr 1 − 2xNb 2 − xScxO 9（x = 0.05，0.10，0.15，0.20），并通过粉末X射线衍射、介电和铁电测量进行了表征。从介电测量获得的铁电到顺电相变温度（Tc）范围为430-731 °C。采用粉末X射线衍射数据对Bi2.2Sr0.8Nb1.9Sc0.1O9（I）的晶体结构进行了精修，结果表明，室温下，I的极性空间群为A21 am（a = 5.5083（4）<$，B = 5.5025（4）<$，c = 25.1741（11）<$; V = 763.01（9）<$3）。I采用非极性空间群，I4/mmm，在550 °C下（I的介电测量的Tc为528 °C）。对I的极化与电场的测量表明，饱和和反射极化分别为11.8 μC cm−2和7.4 μC cm−2。此外，相关的Tc，与公差因子进行了讨论，并与nd 0配置进行了探索。
A new series of ferroelectric Aurivillius oxides containing Sc3+ in the B site in stoichiometric compositions, Bi2+2xSr1−2xNb2−xScxO9 (x = 0.05, 0.10, 0.15, 0.20), were synthesized by a standard solid state method and characterized by powder X-ray diffraction, dielectric and ferroelectric measurements. The ferroelectric to paraelectric phase transition temperature (Tc) obtained from dielectric measurements range from 430–731 °C. Crystal structure refinement on Bi2.2Sr0.8Nb1.9Sc0.1O9 (I) using powder X-ray diffraction data revealed that I crystallizes in polar space group, A21am (a = 5.5083(4) Å, b = 5.5025 (4) Å, and c = 25.1741(11) Å; V = 763.01 (9) Å3), at room temperature. I adopts non-polar space group, I4/mmm, at 550 °C (Tc from dielectric measurement for I is 528 °C). Polarization vs. electric field measurements on I, showed that the saturation and remanent polarizations are 11.8 μC cm−2 and 7.4 μC cm−2 respectively. In addition, the correlation of Tc, with tolerance factors are discussed and, with nd0 configurations are explored.