SrBi2Ta2O9/Bi4Ti3O12复合铁电薄膜的制备与特性研究

采用溶胶凝胶工艺在p-Si衬底上制备了SrBi₂Ta₂O₉/Bi₄Ti₃O₁₂复合铁电薄膜. 研究了SrBi₂Ta₂O₉/Bi₄Ti₃O₁₂复合薄膜的微观结构与生长行为、铁电性能和疲劳特性. 研究表明: Si衬底Bi₄Ti< 关键词： 2Ta₂O₉')" href="#">SrBi₂Ta₂O₉ 4Ti₃O₁₂')" href="#">Bi₄Ti₃O₁₂ 复合铁电薄膜 溶胶凝胶工艺     

Si基Bi3.25La0.75Ti3O12铁电薄膜的制备与特性研究

采用Sol-Gel工艺低温制备了Si基Bi_3.25La_0.75Ti₃O₁₂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Bi_3.25La_0.75Ti₃O₁₂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Bi_3.25La_{0.75 关键词： 铁电薄膜 3.25}La_0.75Ti₃O₁₂')" href="#">Bi_3.25La_0.75Ti₃O₁₂ Sol-Gel工艺     

电场热处理条件下TiO2薄膜的晶化行为研究

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     

Ag/Bi4Ti3O12栅n沟道铁电场效应晶体管制备及存储特性

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/Bi₄Ti₃O_{12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}-V_G)特性曲线显示Ag/Bi₄Ti₃O_{12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 4}Ti₃O₁₂')" href="#">Bi₄Ti₃O₁₂ 存储 特性 溶胶-凝胶工艺     

3BaO·3B2O3·2GeO2非晶体晶化过程的研究

3BaO·3B₂O₃·2Ge0₂是BaO-B₂O₃-GeO₂三元系中的一个三元化合物。本文用差热分析法对3BaO·3B₂O₃·2GeO₂非晶态晶化过程进行了研究,非晶的晶化温度随颗粒度减小而下降。用等温晶化法和峰值位移法测定了不同颗粒度的晶化激活能,非晶颗粒度越小,晶化激活能越大。 关键词：     

NaBO2-B2O3体系玻璃的形成和晶化机制

本文用热学分析、高温和室温X射线衍射分析、红外吸收光谱等方法研究了NaBO₂-B₂O₃体系玻璃的形成、热稳定性和晶化机制。这一体系十分容易形成稳定的非晶玻璃,晶化过程与非晶的宏观状态有关。块状玻璃的晶化温度比非晶粉末高。部分成份晶化后形成不同的物相,熔点也不同。晶化产物的晶体结构类似于玻璃的结构。NaBO₂-B₂O₃体系的电导率用交流阻抗直接测量法测定。玻璃态的电导率比晶态试 关键词：     

非晶锂离子导体B2O3-0.7Li2O—0.7LiCl-xAl2O3晶化过程的正电子湮没一维角关联辐射研究

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：     

非晶态锂离子导体B2O3-0.7Li2O-0.7LiCl-xAl2O3-0.1V2O5的电学性质和电子自旋共振研究

对两种非晶态B₂O₃-0.7Li₂O-0.7LiCl-xAl₂O₃-0.1V₂O₅(x=0.05和0.15),用差热分析、电导率测量、X射线衍射和电子自旋共振进行研究,发现:1)V₂O₅不仅作非晶网络形成剂,而且改变了晶化过程;2)对B₂O₃-Li_{2关键词：}     

退火气压对Bi3.25La0.75Ti3O12铁电薄膜的微观结构和铁电性能的影响

采用sol-gel法在Pt/TiO₂/SiO₂/p-Si(100)衬底上制备了Bi_3.25La_0.75Ti₃O₁₂(BLT)铁电薄膜,研究了在750 ℃时不同退火气压(p_{O2:10^-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： 3.25}La_0.75Ti₃O₁₂')" href="#">Bi_3.25La_0.75Ti₃O₁₂ 铁电性能 sol-gel法 正交化度     

非晶离子导体B2O3-0.7Li2O-0.7LiCl-xAl2O3晶化过程的正电子湮没寿命谱和扫描电子显微镜研究

传统的粉末压片样品严重影响了正电子湮没寿命谱及电子显微镜测量的准确性和重复性。本文克服了以上困难,制出大片非晶离子导体样品,得到了晶化过程正电子湮没寿命谱及扫描电子显微镜研究的新结果。非晶离子导体B₂O₃-0.7Li₂O-0.7LiCl-xAl₂O₃的实验结果发现:Al₂O₃组分不同对非晶态样品在室温下的正电子平均寿命无较大影响。完全晶化后,正电子平均寿 关键词：     

Dielectric properties of Bi4Ti3O12–SrBi4Ti4O15 intergrowth ceramics synthesized by a modified oxalate route

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 2P_r than their constituents BIT and SBTi.     

Ti和蓝宝石的界面反应

在超高真空中用电子束蒸发在抛光的(1102)取向的蓝宝石(α-Al₂O₃)衬底上蒸镀500nm的Ti膜,在恒温炉中退火,然后用XRD(包括一般的和小角度的X射线衍射),AES(俄歇电子谱,包括深度剖面分布和通过界面的谱形分析)和SIMS(二次离子质谱)等表面分析技术详细研究了从室温至850℃,Ti与α-Al₂O₃的固相界面反应.结果表明室温及300℃,30min退火已有反应,Al₂O_{3< 关键词：}     

Processing and some properties of biferroic Bi<Subscript>5</Subscript> Ti<Subscript>3</Subscript> FeO<Subscript>15</Subscript> ceramics

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.     

Ferroelectric and dielectric properties of La/Mn co-doped Bi4Ti3O12 ceramics

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.     

CoxTi1－xO2－δ体材中氢退火引起的铁磁性及结构相变

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Co_xTi_1-xO_2-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CoTiO_{3< /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}Ti_1-xO_2-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     

Determination of the magnetoelectric coupling coefficient from temperature dependences of the dielectric permittivity for multiferroic ceramics Bi5Ti3FeO15

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.     

La掺杂对Bi4Ti3O12薄膜铁电性能的影响

利用Sol-Gel法在Pt/Ti/SiO₂/Si衬底上制备出Bi₄Ti₃O₁₂和Bi_3.25La_0.75Ti₃O₁₂薄膜，研究了La掺杂对Bi₄Ti₃O₁₂薄膜的晶体结构、铁电性能和疲劳特性的影响，发现La掺杂没有改变Bi₄Ti₃O₁₂薄膜的基本晶体结构，并且提高了Bi₄Ti₃O₁₂铁电薄膜的剩余极化值和抗疲劳性能，对La掺杂改善Bi₄Ti₃O₁₂铁电薄膜性能的机理进行了讨论. 关键词： 铁电性能 4Ti₃O₁₂薄膜')" href="#">Bi₄Ti₃O₁₂薄膜 3.25La_0.75Ti₃O₁₂薄膜')" href="#">Bi_3.25La_0.75Ti₃O₁₂薄膜 sol-gel法 La掺杂