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采用Sol-Gel工艺低温制备了Si基Bi3.25La0.75Ti3O12铁电薄膜.研究了退火温度对薄膜微观结构、介电特性与铁电性能的影响.500℃退火处理的Bi3.25La0.75Ti3O12薄膜未能充分晶化,晶粒细小且有非晶团聚,介电与铁电性能均较差.高于550℃退火处理的Bi3.25La0.75
关键词:
铁电薄膜
3.25La0.75Ti3O12')" href="#">Bi3.25La0.75Ti3O12
Sol-Gel工艺 相似文献
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利用溶胶-凝胶法和电场热处理工艺在玻璃表面制备出一层TiO2薄膜,采用DTA ,Raman光 谱,XRD和AFM等测试手段分析了TiO2薄膜在电场热处理过程中的晶化行为.然后 在理论上 分析了外电场对TiO2薄膜热处理过程的影响,提出了通过引入外电场促进TiO2薄膜从无 定形到锐钛矿的相转变的方法.通过甲基橙水溶液的光催化降解实验表明:在520℃电场热处 理条件下的TiO2薄膜的光催化效率高于未引入电场热处理的TiO2薄 膜.
关键词:
薄膜
晶化
电场
2')" href="#">TiO2 相似文献
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在溶胶-凝胶工艺获得高质量Bi4Ti3O12薄膜的基础上 ,制备了Ag/Bi4Ti3O12栅n沟道铁电场效应晶体管. 研 究了Si基Bi4Ti3O12薄膜的生长特性及其对铁电薄膜/ 硅的界面状态和铁电场效应晶体管存储特性的影响. 研究表明,在合理的工艺条件下可以获 得具有较高c-轴择优取向的纯钙钛矿相Si基Bi4Ti3O12 铁电薄膜并有利于改善Bi4Ti3O12/Si之间的界面特性; 顺时针回滞的C-V特性曲线和C-T曲线表明Ag/Bi4Ti3O12栅n沟道铁电场效应晶体管具有极化存储效应和一定的极化电荷保持能力; 器件的转移(I< sub>sd-VG)特性曲线显示Ag/Bi4Ti3O12 sub>栅n沟道铁电场效应晶体管具有明显的栅极化调制效应.
关键词:
铁电场效应晶体管
4Ti3O12')" href="#">Bi4Ti3O12
存储 特性
溶胶-凝胶工艺 相似文献
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本文用中国第一台正电子湮没辐射一维角关联实验装置,测量了非晶锂离子导体B2O-0.7Li2O-0.7LiCl-xAl2O3(x=0.15;0.10;0.05)晶化过程中各条正电子湮没辐射的一维角关联曲线,并对归一化的电子动量分布进行了线形参数的计算,从其S参数同样能推测出该离子导体在晶化过程中缺陷浓度的变化。非晶离子导体B2O3-0.7Li2O-0.7LiCl-xAl2O3的实验结果表明,Al2O3组分不同,对非晶态样品在室温下一维角关联曲线的S参数亦无较大影响。完全晶化后,一维角关联曲线的S参数均有很大下降。在晶化过程最初期,无论Al2O3含量多少,S参数都明显略增;到晶化温度附近,仅对Al2O3含量较多的非晶,S参数反常增高。这些结果验证和补充了测正电子平均寿命得出的结论。由此初步证实了界面层有大量缺陷的物理图象。
关键词: 相似文献
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采用sol-gel法在Pt/TiO2/SiO2/p-Si(100)衬底上制备了Bi3.25La0.75Ti3O12(BLT)铁电薄膜,研究了在750 ℃时不同退火气压(pO2:10-4—3 atm)对薄膜微观结构和电学性能的影响.XRD和拉曼光谱结果表明在10-4和3 atm氧气压下退火
关键词:
3.25La0.75Ti3O12')" href="#">Bi3.25La0.75Ti3O12
铁电性能
sol-gel法
正交化度 相似文献
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Geetanjali Parida 《Phase Transitions》2013,86(5):452-459
In this study, Bi4Ti3O12–SrBi4Ti4O15 (BIT–SBTi) intergrowth ferroelectric ceramics was synthesized by a modified oxalate route. The phase formation behaviour, structure, morphology and electrical properties of the intergrowth ceramics were also investigated. The phase formation takes place through intermediate phases like SrBi2O4 and Bi12TiO20. The precursor mostly changes to Bi4Ti3O12 at 600°C and to BIT–SBTi intergrowth at 800°C. Rietveld analysis of the X-ray diffraction pattern showed that the structure of the intergrowth compound was orthorhombic with lattice parameters a = 5.4408(3), b = 5.4505(1) and c = 74.0851(4) Å. The intergrowth ferroelectrics showed a phase transition at 610°C and a frequency-stable permittivity and dielectric loss behaviour. The intergrowth ferroelectrics also showed a larger 2Pr than their constituents BIT and SBTi. 相似文献
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La/Mn co-doped Bi4Ti3O12 ceramics,Bi3.25La0.75Ti3-xMnxO12(x=0.02,0.04,0.06,0.08),were prepared by the solid-state reaction method.The influence of manganese substitution for the titanium part in Bi 3.25 La 0.75 Ti 3 O 12 on the sintering behaviour,microstructure,Raman spectra and electrical properties was investigated.The experimental results show that the phase composition of all samples with and without manganese doping,sintered at 1000 ℃,consists of a single phase with a bismuth-layered structure belonging to the crystalline phase Bi4Ti3O12.There is no evidence of any impurity phase,but a small change in crystallographic orientation is observed.The Curie temperature of Bi3.25La0.75Ti3-xMnxO12 ceramics is steadily shifted to lower temperature with increasing Mn-doping content.Moreover,the remnant polarisation(Pr) of Bi3.25La0.75Ti2.92Mn0.08O12 samples increases with Mn-doping content,and the Bi3.25La0.75Ti2.92Mn0.08O12 sample exhibits the largest P r of 16.6 μC/cm 2. 相似文献
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J. Rymarczyk D. Machura J. Ilczuk 《The European physical journal. Special topics》2008,154(1):187-190
Bi5Ti3FeO15 (BTF) is an example
of bifferoic Aurivillius phase with perovskite layered structure. Materials
on the basis BTF are of substantial interest for new types of
magnetoelectric device applications. In this review we discuss technology of
preparation biferroic ceramic with composition Bi5Ti3FeO15.
The ferroelectric layered Bi5Ti3FeO15 (BTF) Aurivillius
phases were synthesized by solid-phase synthesis reaction from the
conventional mixture of oxides, viz. Bi2O3, Fe2O3,
TiO2. Thermal analysis and mass change efect were used to investigate
synthesis effects in the stoichiometric mixture of powders. The crystalline
structure was checked by X-ray diffraction method at room temperature.
Microstructure was investigated by scanning electron microscopy. 相似文献
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In the multiferroic materials, the dielectric and magnetic properties are closely correlated through the coupling interaction between the ferroelectric and magnetic order. We attempted to determine the magnetoelectric coupling coefficient from the temperature dependences of the dielectric permittivity for multiferroic Bi5Ti3FeO15. Multiferroic ceramics Bi5Ti3FeO15 belong to materials of the Aurivillius-type structure. Multiferroic ceramics Bi5Ti3FeO15 was synthesized via sintering the Bi2O3 and Fe2O3 mixture and TiO2 oxides. The precursor material was ground in a high-energy attritorial mill for 5 hours. This material was obtained by a solid-state reaction process at T = 1313 K. We investigated the temperature dependences of the dielectric permittivity for the different frequencies. From the dielectric measurements, we determined the temperature of phase transition of the ferroelectric-to-paraelectric type at about 1013 K. Based on dielectric measurements and theoretical considerations, the values of the magnetoelectric coupling coefficient were specified. 相似文献
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S. R. Das P. S. Dobal B. Sundarakannan R. R. Das R. S. Katiyar 《Journal of Raman spectroscopy : JRS》2007,38(9):1077-1081
We have studied the lattice vibrational modes of Zr‐substituted Bi4Ti3O12 ceramics using micro‐Raman spectroscopy. Replacement of Zr at the Ti site in the perovskite block is found from the increase in the lattice parameters as a function of Zr contents. Combined X‐ray diffraction patterns and Raman analysis suggested less than 40 mole% Zr solubility in Bi4Ti3O12. At 40 mole% of Zr substitution or above, the unreacted monoclinic‐phase ZrO2 is observed in the X‐ray diffraction patterns and the Raman spectra. The incorporation of Zr in Bi4Ti3O12 reduces the soft mode wavenumber and the transition temperature. Moreover, temperature dependent studies confirmed the ferroelectric to paraelectric transition in Bi4Ti3O12 at about 675 °C. On increasing the Zr content up to 40% on the Ti sites of Bi4Ti3O12, a systematic decrease in the phase transition temperature from 675 to 630 °C was observed. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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利用固相反应法在700℃—1000℃不同的温度下、空气中烧结Co3O4 和TiO2混合物,制备了(Co3O4)x/3(TiO2)1-x(03,说明Co3O4与TiO2反应形成了CoT iO3;同时,在700 ℃低温和900 ℃以上的高温烧结样品中分别观察到了单相的 锐钛矿和金红石相结构.经高低温烧结的样品在500 ℃氢退火后,CoTiO3相消失 ,锐钛矿相的CoxTi1-xO2-δ形成.X射线光电子能谱(X PS)分析显示,氢退火样品中的Co以+2氧化价态存在,同时没有观察到金属态的Co,这说明 氢退火样品中的室温铁磁性不是源于金属Co颗粒的形成,而是与钙钛矿结构的CoTiO3< /sub>相的消失和锐钛矿型的CoxTi1-xO2-δ相的形成 有关.(Co3O4)x/3(TiO2)1-x( 0x Ti1-xO2-δ相的本征铁磁性,伴随着结构相变而产生的Co离子之间的铁磁交换相互作用或 许是样品室温铁磁性产生的根本原因.
关键词:
室温铁磁性
结构相变
锐钛矿
氢退火 相似文献