微结构对Eu掺杂Bi4Ti3O12铁电薄膜铁电性能的影响

采用金属有机物分解法在Pt/Ti/Si(111)基底上制备了退火温度分别为600℃,650℃,700℃的Bi_3.15Eu_0.85Ti₃O₁₂(BET)铁电薄膜,并对其结构及铁电性能进行了测试,再使用扫描探针显微镜对BET薄膜的电畴翻转进行了实时观测.BET薄膜c畴发生180°畴变的最小电压为+6V,而r畴由于其高四方性,即使极化电压增至+12V也不会发生翻转.薄膜的铁电性主要源于c畴的极化,随着退火温度的升高,c畴的区域面积增加,BET薄膜的剩余极化强度随之增大.退火温度为700℃的BET薄膜剩余极化强度达到84μC/cm². 关键词： 铁电薄膜 电畴翻转 扫描探针显微镜     

Si基Bi4Ti3O12铁电薄膜的制备与特性研究

采用sol-gel工艺, 在分层快速退火的工艺条件下成功地制备了高质量Si基Bi_{4Ti3O12铁电薄膜. 研究了Si基Bi4Ti3O12薄膜的生长行为、铁电性能、C-V特性和疲劳特性. 研究表明: Si基Bi4Ti3O12薄膜具有随退火温度升高沿c轴择优生长的趋势; 退火温度通过影响薄膜的晶粒尺寸、生长取向和薄膜中载流子的浓度来改变Si基Bi关键词： sol-gel法 铁电薄膜 4Ti3O12')" href="#">Bi4Ti3O12 C-V特性}     

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     

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     

SrBi4Ti4O15的化学键性质和铁电性研究

通过原子环境计算方法分析了正交相SrBi₄Ti₄O₁₅晶体内的键络结构、各原子的空间配位数及局域团簇结构. 在此基础上, 结合晶体分解理论将SrBi₄Ti₄O₁₅晶体分解为多个二元赝晶体, 根据化学键介电理论计算得到各赝晶体所对应化学键的有效价电子密度、离子性等化学键性质. 通过键偶极矩建立了铁电体自发极化强度与化学键性质之间的关系, 求得正交相SrBi₄Ti₄O₁₅沿a轴方向的自发极化强度为28.03 μC/cm², 与实验结果和其他理论计算值符合较好.     

La掺杂SrBi4Ti4O15铁电材料性能研究

按x=0.00，0.10，0.25，0.50，0.75和1.00，采用固相烧结工艺，制备了不同La掺杂量的SrBi_4-xLa_xTi₄O₁₅的陶瓷样品. 用x射线衍射对其微结构进行了分析，并测量了铁电、介电性能.结果发现，La掺杂未改变SrBi₄Ti ₄O₁₅的晶体结构.随掺杂量的增加，样品的矫顽场(E_c)下降，剩余极化(2P_{关键词： 4-x}La_xTi₄O₁₅')" href="#">SrBi_4-xLa_xTi₄O₁₅ La掺杂 铁电性能 相变温度 弛豫铁电     

Pb(Zr0.3Ti0.7)O3铁电薄膜激光感生电压效应

采用脉冲激光沉积(PLD)技术在LaSrAlTaO₃(LSATO),LaAlO₃(LAO)和SrTiO₃(STO)的单晶倾斜衬底上成功制备了Pb(Zr_0.3Ti_0.7)O₃(PZT)薄膜,在三种倾斜衬底上生长的PZT薄膜中都首次发现了LIV效应.对PZT/LSATO薄膜在a,c轴两种不同取向择优生长下的LIV效应做了研究,发现在薄膜c轴取向择优生长 关键词： 激光感生电压效应 铁电薄膜 薄膜生长取向 原子层热电堆     

溶胶-凝胶法制备Sr2Bi4Ti5O18薄膜及其铁电性能研究

采用溶胶-凝胶法,在氧气氛中和层层晶化的工艺条件下,成功地制备了沉积在Pt/Ti/SiO₂/Si(100)衬底上的铁电性能优良的Sr₂Bi₄Ti₅O₁₈ (SBTi)薄膜,并研究了SBTi薄膜的微结构、表面形貌、铁电性能和疲劳特性.研究表明：薄膜具有单一的层状钙钛矿结构，且为随机取向；薄膜表面光滑，无裂纹，厚度约为725nm；铁电性能测试显示较饱和、方形的电滞回线，当外电场强度为275kV/cm时 关键词： 溶胶-凝胶法 铁电薄膜 2Bi₄Ti₅O₁₈')" href="#">Sr₂Bi₄Ti₅O₁₈     

外延PbZr0.4Ti0.6O3薄膜厚度对其铁电性能的影响

从Landau-Devonshire唯象理论出发，考虑到晶格失配导致的NFDA3位错应力场与极化场的耦合，研究了在SrTiO₃衬底上外延生长的PbZr_0.4Ti_0.6O₃薄膜厚度对其自发极化强度、电滞回线的影响. 结果表明，产生刃位错的PbZr_0.4Ti_0.6O₃薄膜临界厚度为～1.27nm，当薄膜厚度大于临界厚度时，在所形成的位错附近，极化强度出现急剧变化，形成自发极化强度明显减弱的“死层”；随着薄膜厚度的减小，位错间距增大，“死层”厚度与薄膜总厚度之比增加. 由薄膜电滞回线的变化情况可知，其剩余极化强度随着薄膜厚度的减小而逐渐减小. 关键词： 铁电薄膜 自发极化强度 电滞回线 位错     

PbTiO3/PbZr0.3Ti0.7O3/PbTiO3夹心结构铁电薄膜子晶层的优化

用Sol-Gel法制备了Pb_(1+x)TiO₃/PbZr_03Ti_07O₃/Pb_(1+x)TiO₃(PT/PZT/PT)夹心结构及PZT铁电薄膜,为了获得高质量的PT/PZT/PT夹心结构铁电薄膜,使用不同过量Pb配比(x)的PbTiO₃ (PT)层进行制备,以获得优化的PT子晶层.X射线 关键词： PT/PZT/PT 夹心结构 子晶 铁电薄膜     

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.     

Properties of vanadium-doped SrBi4Ti4O15 ferroelectric ceramics

Using the standard solid-state reaction method, several vanadium-doped ferroelectric ceramics of type SrBi_4−x/3Ti_4−xV_xO₁₅ (SBTV-x) were synthesized. The vanadium doping content, x, ranges from 0.000 to 0.06. The crystal structure of SrBi₄Ti₄O₁₅ is not affected by V-doping. The electric breakdown voltage of the samples increases with V content. Meanwhile, V-doping results in a notable enlargement of remnant polarization (2P_r). The 2P_r of STBV-0.03 reaches a very large value, which is over 50 μC/cm² and is nearly twice greater than that at zero doping. The Curie temperatures of V-doped samples decrease slightly in comparison with that of SrBi₄Ti₄O₁₅. V-doping can improve the electric properties of SrBi₄Ti₄O₁₅ without sacrificing its thermal stableness.     

Properties of vanadium-doped SrBi4Ti4O15 ferroelectric ceramics

Using the standard solid-state reaction method, several vanadium-doped ferroelectric ceramics of type SrBi_4−x/3Ti_4−xV_xO₁₅ (SBTV−x) were synthesized. The vanadium doping content, x, rangs from 0.00 to 0.06. The crystal structure of SrBi₄Ti₄O₁₅ is not affected by V-doping. The electric breakdown voltage of the samples increases with V content. Meanwhile, V-doping results in a notable enlargement of remnant polarization (2P_r). The 2P_r of STBV−0.03 reaches a very large value, which is over 50 μC/cm² and is nearly twice greater than that at zero doping. The Curie temperatures of V-doped samples decrease slightly in comparison with that of SrBi₄Ti₄O₁₅. V-doping can improve the electric properties of SrBi₄Ti₄O₁₅ without sacrificing its thermal stableness.     

Lanthanum-doped Bi4Ti3O12 ceramics prepared by high-pressure technique

We present an effective way in this paper to increase the density of lanthanum doped bismuth titanate ceramics, Bi4-xLaxTi3O12 (BLT), thereby significantly improving the performance of the BLT ceramics. Dense BLT ceramicses, Bi4-xLaxTi3O12 (x = 0.25, 0.5, 0.75, 1.0), are prepared by using nanocrystalline powders fabricated by a-gel method and high-pressure technique. The microstructures of the BLT ceramicses prepared separately by conventional-pressure and high-pressure techniques are investigated by using x-ray diffraction and transmission electron microscope. The influence of La-doping on the densification of bismuth titanate ceramics is investigated. The experimental results indicate that the phase compositions of all samples with various lanthanum dopings sintered at 900°C possess layer-structure of Bi4Ti3O12 . The green compacts are pressed under 2.5 GPa, 3.0 GPa, 3.5 GPa and 4.0 GPa, separately. It is found that the density of BLT ceramics is significantly increased due to the decreasing of porosity in the green compacts by high-pressure process.     

Great enhancement in remnant polarization of SrBi4Ti4O15 thin films by A-site doping of Fe3+ ions

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.     

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     

Mo掺杂SrBi4Ti4O15陶瓷的铁电介电性能

用传统的固相烧结工艺，制备了钼掺杂铁电陶瓷样品SrBi₄Ti₄O₁₅(SBTi)铁电陶瓷SrBi_4-2x/3Ti_4-xMo_xO₁₅(x=0.00，0.003，0.012，0.03，0.06，0.09).X射线衍射的结果表明，样品均为单一的层状钙钛矿结构相，Mo掺杂未改变SBTi的晶体结构.通过扫描电子显微镜观测发现，样品晶粒为片状，随掺杂量的增加，晶粒逐 关键词： 4Ti₄O₁₅')" href="#">SrBi₄Ti₄O₁₅ Mo掺杂 剩余极化 居里温度