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BisFe1-xCoxTi3O15 (x=0.0, 0.2, 0.4, 0.5, 0.6, and 0.8) multiferroic ceramics are synthesized in two steps using the solid state reaction technique. X-ray diffraction patterns show that the samples have four-layer Aurivillius phases. At room temperature (RT), the samples each present a remarkable coexistence of ferromagnetism (FM) and ferroelectricity (FE). The remnant polarization (2Pr) reaches its greatest value of 14 gC/cm2 at x = 0.6. Remnant magnetization (2Mr) first increases and then decreases, and the greatest 2Mr is 7.8 menu/g when x = 0.5. The magnetic properties for x = 0.4 are similar to those for x = 0.6, indicating that the magnetic properties originate mainly from the coupling between Fe3+ and Co3+ ions, rather than from their own magnetic moments. 相似文献
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The doping effects of BiFe<sub>1-x</sub>Co<sub>x</sub>O<sub>3</sub>(x=0.0-0.8) in layered perovskite Bi<sub>4</sub>Ti<sub>3</sub>O<sub>12</sub> ceramics 下载免费PDF全文
Bi5Fe1-xCoxTi3O15(x = 0.0, 0.2, 0.4, 0.5, 0.6, and 0.8) multiferroic ceramics are synthesized in two steps using the solid state reaction technique. X-ray diffraction patterns show that the samples have four-layer Aurivillius phases. At room temperature (RT), the samples each present a remarkable coexistence of ferromagnetism (FM) and ferroelectricity (FE). The remnant polarization (2P r ) reaches its greatest value of 14 μC/cm 2 at x = 0.6. Remnant magnetization (2M r ) first increases and then decreases, and the greatest 2M r is 7.8 menu/g when x = 0.5. The magnetic properties for x = 0.4 are similar to those for x = 0.6, indicating that the magnetic properties originate mainly from the coupling between Fe 3+ and Co 3+ ions, rather than from their own magnetic moments. 相似文献
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脉冲激光沉积法制备高温压电薄膜0.20 BiInO$lt;sub$gt;3$lt;/sub$gt;-0.80PbTiO$lt;sub$gt;3$lt;/sub$gt;$lt;strong$gt;$lt;font color="#ff0000"$gt;$lt;font color="#ff0000"$gt;(已撤稿)$lt;/font$gt;$lt;/font$gt;$lt;/strong$gt; 下载免费PDF全文
采用脉冲激光沉积法制备了0.20BiInO3-0.80PbTiO3(20BI-PT)高温压电薄膜,并与0.15BiInO3-0.85PbTiO3(15BI-PT)样品进行了比较研究. X射线衍射谱显示,20BI-PT样品100峰出现了明显的劈裂,显示样品具有更高的四方对称性. FESEM图显示,20BI-PT样品中出现了部分111取向的三角形晶粒. 20BI-PT样品的铁电剩余极化(Pr)为~28 μC/cm2,矫顽场(Ec)为~120 kV/cm,相较15BI-PT样品,Pr略有增加,但同时Ec也有增加. 20BI-PT样品的横向压电系数(e31,f)约为–4.7±0.6 C/m2,和15BI-PT相比几乎一样. 介电温度谱显示,20BI-PT 样品的居里温度比15BI-PT增加了约30 ℃,达590 ℃,且介电峰没有明显的频率依赖性. Rayleigh分析显示,20BI-PT样品中内在本征因素及可翻转畴对介电非线性的贡献和15BI-PT基本相同,但是外在因素的贡献没有15BI-PT的贡献大,这可能和20BI-PT样品中晶粒111相对取向率较高有关.
关键词:
薄膜
脉冲激光沉积
铁电
压电 相似文献
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Great enhancement in remnant polarization of SrBi4Ti4O15 thin films by A-site doping of Fe3+ ions 下载免费PDF全文
SrBi4-xFexTi4O15 (SBFT-x) thin films (x = 0.00, 0.05, 0.08, 0.15) have been synthesized on Pt/Ti/SiO2/Si (100) substrates by sol-gel method. This paper finds that Fe-doping does not change the crystal structure of SrBi4Ti4O15 (SBTi). The coercive filed (Ec) and remnant polarisation (Pr) increase at first, then decrease with the increase of Fe doping content. At a maximum applied field of 229 kV/cm, the 2Pr reaches a maximum value of 91.1 μC/cm2 at x = 0.05 and the corresponding Ec is 72 kV/cm. The 2Pr increases by about 260% and the Ec decreases by about 6%, respectively. Obviously, the ferroelectric property of SrBi4Ti4O15 is greatly enhanced by Fe doping. The fatigue-endurance characteristic of the SBFT-0.05 is not improved. After 1.1×109 read/write cycles at a frequency of 50 kHz, the nonvolatile polarisations (Pnv = P*-P∧) decreased about 48% of its initial value. 相似文献
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Structure, ferroelectric and dielectric properties of Bi2WO6 with different bismuth content 下载免费PDF全文
This paper reports that the Bi 2 WO 6 ferroelectric ceramics with excess Bi 2 O 3 of 0.0, 2.0, 3.5 and 5.0 wt.% of the stoichiometric composition are prepared by the conventional solid-state reaction method. Their microstructure, ferroelectric properties, the concentration and mobility of the defects have been analysed systematically. With increasing Bi content, the remnant polarization decreases, and the broken-down voltage increases. The optimum Bi excess, 3.5, lowers the oxygen vacancy concentration, while further Bi-addition brings about more defects. The activation energies fitted from cole-cole plots are 0.97 eV, 1.07 eV, 1.18 eV, and 1.33 eV, respectively. This suggests that the mobility of the defects is weakened by Bi-addition, which may be due to the increase of the ratio of the number of Bi 2 O 2 layers to that of the perovskite blocks. 相似文献
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采用柠檬酸-硝酸盐法制备了Bi_(6-x)Nd_xFe_(1.4)Ni_(0.6)Ti_3O_(18)(BNFNT-x,x=0.00,0.10,0.20,0.25和0.30)前驱液,再经过干燥、烧结过程制备了单相多晶材料.研究发现,少量Nd掺杂有助于提高样品的铁电性能,BNFNT-0.25样品的铁电性能(2Pr)最大,约达到19.7μC/cm~2.室温下BNFNT-0.20样品磁性能(2Ms)最大约达到4.132 emu/g(1 emu/g=10–3 A·m~2/g).变温介电损耗结果表明Nd掺杂降低了Fe~(3+)和Fe~(2+)间的电子转移或跃迁的激活能.X射线光电子能谱结果表明小量Nd掺杂有助于增强Bi离子稳定性,对改善样品的铁电性能有积极意义. 相似文献
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Co-doped Bi 5 FeTi 3 O 15 thin films (BFCT-x,Bi 5 Fe 1-x Co x Ti 3 O 15) were prepared using a sol-gel technique.XRD patterns confirm their single phase Aurivillius structure,and the corresponding powder Rietveld analysis indicates the change of space group around x=0.12.The magnetic hysteresis loops are obtained and ferromagnetism is therefore confirmed in BFCT-x thin films.The remanent magnetization (M r) first increases and reaches the maximum value of 0.42 emu/cm 3 at x=0.12 due to the possible Fe 3+-O-Co 3+ ferromagnetic coupling.When x=0.25,the M r increases again because of the dominant Fe 3+-O-Co 3+ ferromagnetic coupling.The remanent polarization (2P r) of BFCT-0.25 was measured to be as high as 62 μC/cm 2,a 75% increase when compared with the non-doped BFCT-0 films.The 2P r remains almost unchanged after being subjected to 5.2 × 10 9 read/write cycles.Greatly enhanced ferroelectric properties are considered to be associated with decreased leakage current density. 相似文献