TiO2种子层对Bi 3.15 Nd 0.85 Ti 3 O 12铁电薄膜的结晶取向和铁电性能的影响

用sol—gel法分别制备了直接沉积在Pt／Ti／SiO2／Si衬底上和加入了TiO2种子层的Bi3．15Nd0．85Ti3O12（BNT）铁电薄膜，研究了种子层对BNT薄膜结构和电学性能的影响．XRD结果表明直接沉积在Pt／Ti／SiO2／Si衬底上的BNT薄膜具有（117）和（001）的混合取向，而加入TiO2种子层之后薄膜的最强峰为（200）取向；FE-SEM显示具有TiO2种子层的BNT薄膜，其表面主要是由具有非C轴取向的晶粒组成且更为致密；直接沉积的BNT薄膜和具有TiO2种子层的BNT薄膜的剩余极化Pr值分别为26和43．6μC／cm^2，矫顽场强＆分别为91和80．5kV／cm；疲劳测试表明两种薄膜均具有良好的抗疲劳特性，TiO2种子层的引入并没有降低BNT薄膜的疲劳特性；两种薄膜的漏电流密度均在10^-6-10^-5A／cm^2之间．     

有机凝胶法制备Sr0.5Ba0.5Nb2O6铁电薄膜及其电性能研究

采用有机凝胶法制备了Sr0．5Ba0.5Nb2O6(SBN50)铁电薄膜．研究了pH值和EDTA的用量对Sr-Ba-Nb前驱体溶液稳定性的影响，并对不同pH值条件下获得的Sr-Ba-Nb干凝胶的热分解历程进行了对比．计算和实验结果表明，制备Sr-Ba-Nb前驱体溶液的最佳pH=8，EDTA：金属离子(摩尔比)=2：1．在700℃下退火30min所得SBN50薄膜为单一钨青铜结构多晶薄膜．室温下，测试频率1kHz时，薄膜的介电常数为221，介电损耗为0．02，剩余极化强度Pr=8．17μC／cm^2，矫顽场Ec=16．9kV／cm．     

MOD法制备的Bi3.25Nd0.75Ti3O12薄膜的铁电各向异性行为

采用金属有机分解法(MOD)在(111)Pt／Ti／SiO2／Si衬底上制备了含(117)成分的c轴择优取向和α轴择优取向的Bi3.25Nd0.75Ti3O12(BNT)薄膜．实验发现，BNT薄膜的品型结构主要依赖于预退火条件．电学性能测试表明，α轴择优取向的BNT薄膜具有高的剩余极化和矫顽场，较高的介电常数和介电损耗，以及较大的电容调谐率；而c轴择优取向的则相反．BNT薄膜具有同Bi4Ti3O12(BIT)薄膜相似的铁电各向异性行为．     

水热合成单晶La 1-x Ca x MnO3系列纳米线

采用水热法，成功地合成了一系列单晶La1-xCaxMnO3（x=0．3、0．5、0．75）纳米线．X射线衍射（XRD）的结果表明所制备的样品是纯的La1-xCaxMnO3正交相（x=0．3、0．5、0．75）纳米线．透射电子显微镜（TEM）的照片清晰地显示所制备的样品是由大量直径均匀（约90nm）、长度从几微米至几十微米的La1-xCaxMnO3的单晶纳米线构成．La0．5Ca0．5MnO3纳米线清晰的高分辨电子显微镜（HRTEM）的图片表明纳米线的表面是光滑的。没有任何缺陷且La0．5Ca0．5MnO3纳米线沿〈100〉方向生长．La0．5Ca0．5MnO3纳米线磁测量的结果表明相对于块材来说纳米线的疋有明显地提高，这是由于晶胞收缩和形状各向异性所致．     

BaPbO3 导电薄膜的制备、结构及性能研究

以可溶性无机盐为原料，EDTA、柠檬酸、酒石酸为复合螯合剂，水为溶剂，采用改进的溶胶-凝胶法制备了无裂纹、晶粒尺寸小且均匀分布的钙钛矿结构的BaPb03导电薄膜．利用XRD、SEM和EDS表征方法结合薄膜方阻的测定，具体分析了Pb／Ba比和晶粒生长情况对BaPbO3薄膜导电性能的影响．实验结果表明：Pb／Ba比和晶粒生长情况是决定BaPbO3薄膜导电性的两个主要因素，Pb／Ba比的上升和晶粒的长大，都会提高BaPbO3薄膜的导电性能；热处理次数对BaPb03薄膜方阻的影响与薄膜厚度有关．在700℃下保温10min的快速热处理方法，可以获得钙钛矿结构、薄膜方阻为5．86Ω．口-1的BaPbO3薄膜．     

Bi4Ti3O12薄膜的取向生长及其电性能研究

采用Sol—Gel工艺，在快速退火的工艺条件下制备了Bi4Ti3O12铁电薄膜，研究了退火温度及时间、薄膜厚度对Bi4Ti3O12薄膜的取向生长行为及其铁电性能、漏电流的影响，探讨了Bi4Ti3O12薄膜取向生长的微观机制．结果表明：退火温度显著影响薄膜的C轴取向生长，其(00ι)品面的取向度F=(P—P0)／(1-P0)由550℃的0．081增加到850℃的0．827，退火时间对其(00ι)晶面的取向度也有较大影响；经750℃以上温度退火处理的Bi4Ti3O12薄膜呈高度c轴取向，对铁电性能有较明显的削弱作用；薄膜的漏电流密度随退火温度升高而增大，但薄膜的c轴取向生长有利于减缓漏电流密度的增长。     

流延成型制备(Na0.85K0.15)0.5Bi0.5TiO3陶瓷的显微结构及性能

采用流延成型工艺制备了（Na0.85K0.15）0．5Bi0.5TiO3无铅压电陶瓷，研究了陶瓷退火前后的显微组织结构，结果表明陶瓷主晶相为钙钛矿相结构，并伴随有形貌呈针状的第二相K2Ti6O13出现；陶瓷断面和表面的晶粒形貌有差别，采用退火处理无法消除第二相K2Ti6O13，但可有效改善陶瓷断面的晶粒形貌，同时增大材料的矫顽场，并使剩余极化强度（Pr）、压电常数（d33）、介电常数（ε）与介电损耗（tanδ）变小．（Na0.85K0.15）0.5Bi0．5TiO3无铅压电陶瓷的电滞回线表现出明显铁电体的特征，其矫顽场为2680V／mm，Pr达36．6μC／cm^2，d33达113pC／N，‰为0．27，Qm达154．     

MOD法制备的Pb0.985La0.01(Zr0.4Ti0.6)O3

采用金属有机分解法(MOD)在LNO(100)／Si衬底上制备了Pb0．985La0．01(Zr0．4Ti0.6)O3铁电薄膜，在薄膜的快速退火过程中，增加了一个中间温度预退火过程，并研究了该过程对薄膜晶型结构和铁电性能的影响．结果发现，中间温度预退火过程可以影响薄膜对晶型结构的选择．没有中间温度预退火过程的薄膜，显示出(100)择优取向；而经中间温度预退火的薄膜则表现为随机取向．对薄膜铁电性能的研究表明，没有中间温度预退火过程的薄膜的铁电性能较差，经380℃预退火的薄膜显示出最佳的铁电性能．晶型结构取向和缺陷是影响PLZT。薄膜铁电性能的两个主要因素．     

飞秒脉冲激光沉积 Si基α轴择优取向的钛酸铋铁电薄膜及I-V特性研究

采用飞秒脉冲激光沉积系统，在Si（111）衬底上制备了α轴和c轴择优取向的Bi4Ti3O12薄膜．X射线衍射（XRD）表明；室温（20℃）下沉积的Bi4Ti3O12／Si（111）薄膜呈C轴择优取向，晶粒的平均直径为20nm．在500℃沉积的Bi4Ti3O12／Si（111）薄膜呈α轴择优取向．测量了薄膜的电滞回线和，I-V特性曲线，并用分布参数电路研究了Bi4Ti3O12薄膜的，I-V特性曲线和铁电性的关联性．α轴择优取向Bi4Ti3O12薄膜的剩余极化强度Pr=15μC／cm^2，矫顽力Ec=48kV／cm．     

Pr6O11掺杂对ZnO-Bi2O3系压敏材料性能影响的研究

采用稀土氧化物Pr6O11对ZnO—Bi2O3系压敏材料进行了改性研究，探讨了Pr6O11对该材料主要性能及微观结构的影响．结果表明，Pr6O11掺杂量较小时，能够显著提高ZnO压敏材料非线性系数，减小漏电流，并基本不影响压敏电压．当Pr6O11掺杂达到一定量时，在保持较高非线性系数，较小漏电流的同时，压敏电压与不含Pr6O11的ZnO压敏材料相比提高约60％；XRD、SEM等分析表明Pr6O11的引入改变了原有材料的微观结构组织，使该材料微观结构中ZnO晶粒尺寸减小，分布均匀、致密．     

脉冲激光法外延生长锰氧化物薄膜

利用脉冲激光法在ＬａＡｌＯ３衬底上外延生长了Ｌａ－Ｃａ－Ｍｎ－Ｏ、Ｌａ－Ｓｒ－Ｍｎ－Ｏ等巨磁电阻薄膜,测定了这些薄膜电阻－温度特性,观测到了其铁磁转变及巨磁电阻效应,实验发现,较高的淀积温度使薄膜的峰值转变温度Ｔｐ降低,峰值电阻率增大,而高温后退火则具有相反的效果,分析比较了多种因素对薄膜生长与性能的影响及其机理。     

Structural and electrical characteristics of chemical solution derived (Bi3.2La0.4Nd0.4)Ti3O12 thin films

(Bi_3.2La_0.4Nd_0.4)Ti₃O₁₂ (BLNT) thin films were prepared on Pt/Ti/SiO₂/Si substrates by using chemical solution deposition technique, and the effects of annealing temperatures in the range of 550-750 °C on structure and electrical properties of the thin films were investigated. X-ray diffraction analysis shows that the thin films have a bismuth-layered perovskite structure with preferred (117) orientation. The surface morphology observation by field-emission scanning electron microscopy confirms that films are dense and smooth with uniformly distributed grains. The grain size of the thin films increases with increasing annealing temperature; meanwhile, the structural distortion of the thin films also increases. It was demonstrated that the thin films show good electrical properties. The dielectric constant and dielectric loss are 191 and 0.028, respectively, at 10 kHz for the thin film annealed at 600 °C, and the 2Pr value of the thin film annealed at 700 °C is 20.5 μC/cm² at an electric field of 500 kV/cm.     

Sn1−x Pbx O2 sputtered thin films as photoanodes for photoelectrochemical cells

Pb_x Sn_1?x O₂ thin films have been prepared by glow discharge. These films have been characterized by X-ray and microprobe analysis. The photoelectrochemical behaviour shows anodic and cathodic corrosion either in the dark or under illumination. The onset of photocurrent is pH dependant. Photocurrent versus the wavelength is shifted to the visible range of the spectrum when lead content increases.     

Lattice Effect on Magnetic and Electrical Properties of Ln2/3Pb1/3MnO3 （Ln=La,Pr, Nd） Films

Lattice effect on magnetic and electrical transport properties of Ln2/3Pb1/3MnO3 （Ln=La, Pr, Nd） films prepared by RF magnetron sputtering technique were investigated. With the decrease of the average ions radius 〈rA〉, the structure of Ln2/3Pb1/3MnO3 （Ln=La, Pr, Nd） targets transit from the rhombohedral phase to the orthorhombic phase, and the Curie temperature reduces rapidly with the decrease of 〈rA〉. The electrical properties show that films are the metallic state which can be fitted to the formula： ρ（T）=ρ0 ＋ ρ1T^2 ＋ ρ2T^4.5 at low temperatures. The temperature range of the ferromagnetic metallic state becomes narrow with the decrease of 〈rA〉. The phenomenon can be explained by the lattice effect.     

Ferroelectric BiFeO3-PbTiO3 thin films on Pt/Si substrates

In this work we report on the preparation and properties of bismuth ferrite lead titanate films [(1- x)BiFeO(3-x)PbTiO3] with tetragonal compositions (x = 0.8 and 0.7) and compare them with compositions close to the morphotropic phase boundary (MPB; x = 0.4 and 0.3). The films were prepared by pulsed laser deposition on Pt/Si substrates, and exhibited a dense columnar grain growth. X-ray diffraction analysis revealed that the films have a perovskite structure with a preferred (111) texture. The dielectric properties, polarization-field hysteresis, and leakage current behavior of the films is also reported. For MPB compositions, the films exhibited remanent polarizations with 2Pr up to 100 microC cm(-2) and E(c) approximately 185 kV cm(-1) under a maximum applied field of 500 kV cm(-1), while the tetragonal compositions exhibited 2Pr values in the range of 45-52 microC cm(-2) with a coercive field E(c) approximately 118 kV (-1).     

Electrochemical deposition of MoS2 thin films by reduction of tetrathiomolybdate

Molybdenum sulphide was cathodically electrodeposited from aqueous solutions of sodium tetrathiomolybdate. The as-deposited films were X-ray amorphous with a composition, measured by microprobe analysis, close to MoS₂. Annealing these films in Ar resulted in highly-textured films of MoS₂ with the van der Waals planes parallel to the substrate. A small expansion in the c spacing of the annealed films was explained by the presence of oxygen in the crystals. A direct bandgap of 1.78 eV was found for the annealed films.     

Surface and Interface Analyses of UHV Evaporated Nb/AlOx/Nb Tri-layers

We have prepared Nb thin films with e-beam evaporation under UHV conditions. Al thin films were deposited by resistive heating in the UHV chamber. The preparation of these films and the tri-layers of Nb/AlOx/Nb were intended for their use in Josephson junctions. The surface studies of these films were undertaken by using scanning electron microscope and atomic force microscope in the non-contact mode, whilst the interface analysis was carried out by depth profiling using scanning Auger microprobe. These studies have revealed that Nb films grown on AlOx are smoother than the ones grown on Si. Further, it is seen that Al diffuses into Nb on both sides and that the interface is very broad. This intermixing of various materials results in the failure of the tri-layers when subjected to application in SQUIDs.     

La/TiO2-SiO2薄膜的光催化性能研究

采用溶胶-凝胶法制备了不同掺杂量的La／TiO2-SiO2复合薄膜．通过XRD、FE-SEM和AFM研究了复合薄膜的微观结构，采用紫外光照射下亚甲基蓝的分解实验比较薄膜的光催化性能．结果表明：La掺杂可显著提高TiO2-SiO2复合薄膜的光催化活性，以5％掺杂量为最佳，其光降解率比掺杂前提高了约23％．薄膜活性提高的主要原因是La掺杂后细化了TiO2的晶粒，提高了薄膜的比表面积，使其具有更高的氧化还原电势，La^3＋取代Ti^4＋进入到TiO2晶格，引起晶格膨胀，这种不同价离子的取代导致TiO2粒子表面电荷分布不平衡，从而提高了光生电子-空穴的分离效率．     

PEO-LiClO4-Li1.3Al0.3Ti1.7 (PO4)3复合聚合物电解质电导率

将实验室烧制的无机快离子导体盐Li_1.3Al_0.3Ti_1.7 (PO₄)₃ 、PEO 与LiClO₄ 按照EO/ Li = 8, 两种锂盐含量为变量进行复合, 通过溶液浇注法制备得到PEO-LiClO₄-Li_1.3Al_0.3Ti_1.7 (PO₄)₃ 复合聚合物电解质膜, 以示差扫描热分析法(DSC) 与电化学阻抗( EIS) 测试其性能。DSC 测试结果表明: 按照EO/ Li = 8 将Li_1.3Al_0.3Ti_1.7 (PO₄)₃ 、LiClO₄ 与PEO 复合的聚合物电解质中PEO 的结晶度由50.34 %下降到4.36 %～28.53 %。室温下该聚合物电解质所有试样的阻抗谱图在高频区呈现为压缩的半圆, 在低频区为一条倾斜的直线, 而在较高温度时, 阻抗谱图主要为一条倾斜的直线。复合聚合物电解质PEO-LiClO₄-Li_1.3Al_0.3Ti_1.7 (PO₄)₃ 的离子电导率遵从Arrhe2nius 关系, 在Li_1.3Al_0.3Ti_1.7 (PO₄)₃ 质量分数达到15 %时, 活化能最低, 即4.494425 eV, 此时电导率值最佳, 373 K时为1.161 ×10 -3 S/ cm 和298 K时为7.985 ×10-6 S/ cm。     

New transparent conducting MgIn2O4---Zn2In2O5 thin films prepared by magnetron sputtering

New materials for a transparent conducting oxide film are demonstrated. Highly transparent Zn₂In₂O₅ films with a resistivity of 3.9 × 10⁻⁴ Ω cm were prepared on substrates at room temperature using a pseudobinary compound powder target composed of ZnO (50 mol.%) and In₂O₃ (50 mol.%) by r.f. magnetron sputtering. MgIn₂O₄---Zn₂In₂O₅ films were prepared using MgIn₂O₄ targets with a ZnO content of 0–100 wt.%. The resistivity of the deposited films gradually decreased from 2 × 10⁻³ to 3.9 × 10⁻⁴ Ω cm as the Zn/(Mg + Zn) atomic ratio introduced into the films was increased. The greatest transparency was obtained in a MgIn₂O₄ film. The optical absorption edge of the films decreased as the Zn/(Mg + Zn) atomic ratio was increased, corresponding to the bandgap energy of their materials. It was found that the resistance of the undoped Zn₂In₂O₅ films was more stable than either the undoped MgIn₂O₄, ZnO or In₂O₃ films in oxidizing environments at high temperatures.