铅对(Pbx,Sr1-x)0.85Bi0.1TiO3薄膜结构与介电可调性影响的研究

用溶胶-凝胶法制备了（Pbx，Sr1-x）0．85Bi0．1TiO3薄膜，对其晶相结构、微观形貌和介电可调性进行了研究．结果表明，该薄膜以钙钛矿形式存在．快速热处理过程可分解得到高活性离子，直接形成比相应温度平衡状态析晶时更多的晶相量．这种晶相在一定条件下有分解和再结晶的趋势．随着Pb^2＋离子增加和Sr^2＋离子减少，钙钛矿相的四方相与立方相间的转变温度升高．薄膜处在铁电相和顺电相转变点附近时，可以获得较大的可调性．     

热处理条件对sol-gel法Pb0.4Sr0.6TiO3薄膜形成影响的研究

采用sol-gel法，利用快速热处理工艺过程，保持烧结温度在最低温度(约500℃)以上，制备了多晶钙钛矿结构的PST(Pb0．4Sr0.6TiO3)薄膜．通过XRD、SEM、AFM等方法对晶相的形成与热处理条件之间的关系进行了测试．研究表明，利用溶胶-凝胶法制备PST薄膜的钙钛矿晶相形成过程及晶相含量受制备过程及晶相形成时离子的活性所控制．通过快速热处理方法，在凝胶分解过程中得到的高活性离子直接形成晶相，可以得到相应更多的晶体含量及在较低的温度下形成晶相．在600℃下RTP制备的PST薄膜的晶相含量比同温度下保温热处理薄膜增加约14％，利用RTP制备PST薄膜的晶相形成温度约在500℃，相应要降低约50℃．薄膜的表面形貌受制备热处理过程影响，快速热处理薄膜的表面保持形成时的形貌：非晶相薄膜以光洁表面出现，晶态膜以均匀分布山峰状的形貌出现．受气氛的浸蚀作用，长时间热处理后的薄膜表面出现了变化，在原形貌的基础上以细小颗粒状覆盖的表面出现．     

Pb1-xCaxTiO3薄膜制备与微观形态表征

采用溶胶凝胶法（s01-gel）在si（100）衬底上制备了掺钙钛酸铅薄膜。利用DTA-TGA考察不同钙掺杂量对晶化温度的影响；用X射线衍射技术（XRD）研究了钙的不同掺杂量对钛酸铅薄膜的结构的影响；同时用原子力电子显微镜（AFM）对薄膜的表面形貌进行研究考察掺钙对钛酸铅薄膜形貌的影响。     

纳米烧绿石型钛酸铅的水热合成

钙钛矿结构的钛酸铅是重要的电子陶瓷材料,在合成钙钛矿型钛酸铅的过程中,经常出现烧绿石结构的钛酸铅物相,但目前尚未见到合成单一物相烧绿石结构的钛酸铅报道.本文报道了用水热法制备烧绿石型钛酸铅纯相的结果,以及体系的碱度对产物的种类和形貌的影响.     

溶胶-凝胶法合成PZT-TiNi复合膜

以醋酸铅、异丙醇锆和钛酸正丁酯为先驱物,利用溶胶-凝胶技术在TiNi形状记忆合金箔基片上成功合成PZT铁电陶瓷薄膜,并研究了PZT薄膜的晶化过程.结果表明,所得PZT薄膜属钙钛矿结构无裂纹,与TiNi合金基片结合牢固.     

溶胶—凝胶法制备PZT薄膜晶化过程升温实验研究

用不同升温速率控制ＰＺＴ薄膜晶化过程，实验结果表明，当晶化温度在４００￣６００℃时，薄膜显然绿石相，当采用较高升温速率５０℃／ｍｉｎ时，在硅片上可缩小焦绿石相生成，提高钙钛矿相形成，从而获得取向性高的钙钛矿相ＰＺＴ薄膜。     

非水解和水解溶胶-凝胶法合成钛酸铝粉体的研究对比

分别采用非水解和水解溶胶-凝胶法合成钛酸铝粉体,利用FT-IR、DTA-TG、XRD、SEM等方法研究了溶胶-凝胶转变和合成相变化过程及粉体烧结性能.结果发现:水解凝胶过程中Al3+以网络外离子形式富集于Ti-O-Ti凝胶网络之间,凝胶依次晶化成金红石和刚玉,再通过固相扩散在1350℃时合成钛酸铝,粉体粒径为1～2μm,比表面积仅3.2m2/g,1400℃烧结后抗弯强度为7.2MPa.非水解凝胶化过程中Al3+和Ti4+通过聚合共同形成凝胶网络,其在网络结构中地位趋同,凝胶在 750℃已直接由无定型晶化为钛酸铝,粉体粒径为0.1～0.3μm,比表面积与抗弯强度分别为水解法样品的35倍和2.3倍,性能较好.     

用溶胶凝胶法制备PZT铁电体薄膜

本文选择非极性溶剂ＡｃＡｃ在大气中保护金属醇盐制备钛锆酸铅（ＰＺＴ）铁电体薄膜，当ＰＺＴ〈０．５ｍｏｌ／Ｌ时可生成稳定溶胶，ＰＺＴ能均匀分散在溶剂中，在４００℃除去残余有机物，然后在４００￣７００℃使薄膜晶化生成钙钛矿结构为主的多晶薄膜。本文利用ＸＲＤ、ＴＥＭ、ＩＲ及热分析技术对ＰＺＴ薄膜的形成及晶化等变化进行了分析和探讨。     

PEG1000用量对多孔TiO_2薄膜结构及光催化性能的影响

以钛酸四丁酯为钛源,PEG1000为模板剂,乙酰丙酮为稳定剂,制备了TiO2溶胶,通过浸渍-提拉法在载玻片上制备了多孔TiO2薄膜。采用X射线衍射、扫描电镜、紫外-可见透射光谱、X射线光电子能谱、N2吸附-脱附等对TiO2薄膜的晶相结构、表面形貌、化学组成及TiO2粉体的BET比表面积和孔径分布进行了表征。考察了TiO2薄膜对甲基橙的光催化降解活性。实验结果表明,TiO2薄膜催化剂的晶型为锐钛矿型,Ti以Ti4+形式存在。随着PEG1000添加量的增加,薄膜表面形貌变得粗糙,孔数量先增加而后下降;多孔TiO2薄膜在紫外区域内的吸收边沿向短波方向移动,薄膜透射率也发生波动,但薄膜的厚度基本不变。当PEG1000添加量为2.0g时,薄膜中存在大量的介孔,薄膜的比表面积最大,光催化性能最佳。     

钛酸铅陶瓷的快速制备及电性能研究

针对传统的Slo-gel法制备钛酸铅铁电陶瓷水解速率慢、烧结温度高、制备周期长等不足，首次采用在溶胶中直接加甲醇水溶液水解和新鲜凝胶直接烧结的方法，实现了钛酸铅纳米晶的快速合成。用TEM观察了钛酸铅纳米晶的形貌和尺寸，用XRD法测定了钛酸铅纳米晶的结构，并制得纯度高、致密性好的钛酸铅纳米陶瓷，对其介电、铁电和热释电性能进行了初步研究。研究表明，用改进的Sol-gel法制备的钛酸铅陶瓷仍保持其优良的介电性能和铁电性能。     

Synthesis and optical absorption property of ordered macroporous titania film doped with Ag nanoparticles

Ordered macroporous anatase titania films doped with Ag nanoparticles (NPs) were synthesized by infiltrating titania sol into the interstitial voids of polystyrene colloidal sphere templates, removing the templates, immersing the films in a silver nitrate solution, and subsequently reducing in hydrogen atmosphere. Ag NPs were distributed uniformly within the macropores of the anatase titania film. Both the macroporous titania films doped with Ag NPs and those without doping have a blue-shift compared with that of the sol–gel derived titania film. Except for the plasma resonance absorption of Ag NPs, the macroporous titania film doped with Ag NPs also has a red-shift compared with the undoped sample. The macroporous titania film doped with Ag NPs have potential applications in the fields of optics, gas sensors, and catalysis.     

Effect of lead on formation and dielectric tunability of (Pbx,Sr1–x)0.85Bi0.1TiO3 thin films

(Pb_x,Sr_{1 x})_0.85Bi_0.1TiO₃ thin films with the perovskite phase structure were prepared on an ITO glass substrate by sol-gel method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and an impedance analyzer were respectively used in order to characterize the phase status, morphology and dielectric properties of the thin films. The results show that during the formation process of (Pb_x, Sr_{1 x})_0.85KBi_0.1TiO₃ thin films, the nucleus of the perovskite phase are initially formed and then congregated. These aggregated nucleus are then transformed as the perovskite-phase crystalline in the thin film. Finally, the crystalline phase grows and separates gradually to form the perfect crystalline-phase structure. The content of the perovskite phase formed in the thin film under rapid thermal process (RTP) is more than that formed under traditional heat treatment with kinetic equilibrium. This is due to the high active decomposed ions that form the perovskite phase directly when heat-treated by RTP. The formation of the perovskite phase therefore overcomes a much lower barrier under RTP than that under traditional calcinations. The structure of the perovskite phase has a close relation to the ratio of Pb/Sr in the system because of the radius difference between Pb²⁺ and Sr²⁺. The transformation temperature between the cubic and the tetragonal structures of the perovskite phase increases with increasing Pb²⁺ content because the radius of Pb²⁺ is larger than that of Sr²⁺. It appears at room temperature when the content of Pb²⁺/Sr²⁺ is about 40/60 in the thin film. Meanwhile, the tetragonality of the perovskite phase is increased when Pb²⁺ ions increase due to its high polarization. The higher tunability of the (Pb_x,Sr_{1 x})_0.85Bi_0.1TiO₃ thin film is exhibited when the film composition is close to the transformation point between the paraelectric and ferroelectric phases. Pb²⁺ions show a dominant factor to affect the Curie point of the system and then changing tunability.     

Synthesis of nanocomposite thin films containing Ag-Au alloy colloids for wavelength tunability

A chemical solution deposition route to synthesize silver-gold alloy colloids in thin films with diameters between 8–35 nm has been developed. Ag-Au alloy colloids were synthesized by the addition of silver ions to a polymer protected aqueous gold sol in presence of a seeding agent 'hydroxylamine hydrochloride,' followed by a heat-treatment under reducing atmosphere at temperatures ranging from 150–550°C. The resonance wavelength of Ag-Au alloy colloids exists between those of pure Ag (410 nm) and pure Au (525 nm) colloids, which can easily be controlled by selecting the molar ratio of Ag to Au. This allows the tunability of the absorption wavelength (hence the color) by using Ag-Au alloy colloids in thin films.     

PZT纳米晶薄膜的Sol—Gel法制备及铁电性质

采用Ｓｏｌ－Ｇｅｌ法，以Ｚｒ的硝酸盐替代醇盐，引入ＰｂＴｉＯ３过渡层的方法成功的制备了纳米晶铁电薄膜。并进行了差热、热重、结构、组分、铁电性能的测定、分析。     

BaPbO3 conductive coating layers on platinized Si substrate for the growth of PbZr1−xTixO3 thin films

Barium metaplumbate (BaPbO₃, BPO) thin films were prepared on Pt/Ti/SiO₂/Si substrates by a sol–gel method and a rapid thermal annealing (RTA) process. X-ray diffraction (XRD) was used to characterize the crystalline structure of the resultant films. It was shown that the formation of perovskite BPO greatly depends on the lead concentration and the final annealing temperature. In terms of the semi-quantitative energy dispersion spectrum (EDS) analysis, the ratio of Pb/Ba in the BPO ceramic films increases as the final heating temperature increases. Using BPO as buffer layers, PZT thin films with a pure perovskite structure were grown at a very low temperature of 500 °C by the sol–gel technique and the RTA process. The remanent polarization of Pt/PZT/BPO/Pt ferroelectric capacitors is about 17 μC/cm² at an applied voltage of 3 V.     

Morphology controlled fabrication and ferroelectric properties of vertically aligned one-dimensional lead titanate nanoarrays

Vertically aligned nanowires and highly uniform nanoporous array thin films of PbTiO(3) are synthesized by varying anodic oxidation conditions of Ti foil followed by hydrothermal reaction in an aqueous Pb(II) acetate trihydrate solution. As-synthesized samples have single crystalline nanowire structure and polycrystalline nanoporous structure, although both are pure PbTiO(3) with a tetragonal phase. The structure of intermediate TiO(2) films obtained from different anodic oxidation conditions determines the structure of the product PbTiO(3). The relationships between these morphological structures and ferroelectric properties are investigated. Piezoresponse force microscopy reveals that both these films show ferroelectricity with clear phase contrast and well-defined hysteresis loops. The saturated longitudinal piezoelectric coefficient field (E(c)) of the nanowire sample is smaller than that of nanoporous thin film. Thus, polarization of nanowire thin film is larger in magnitude and easier to flip than that of nanoporous film.     

Large‐Grain Tin‐Rich Perovskite Films for Efficient Solar Cells via Metal Alloying Technique

Fast research progress on lead halide perovskite solar cells has been achieved in the past a few years. However, the presence of lead (Pb) in perovskite composition as a toxic element still remains a major issue for large‐scale deployment. In this work, a novel and facile technique is presented to fabricate tin (Sn)‐rich perovskite film using metal precursors and an alloying technique. Herein, the perovskite films are formed as a result of the reaction between Sn/Pb binary alloy metal precursors and methylammonium iodide (MAI) vapor in a chemical vapor deposition process carried out at 185 °C. It is found that in this approach the Pb/Sn precursors are first converted to (Pb/Sn)I₂ and further reaction with MAI vapor leads to the formation of perovskite films. By using Pb–Sn eutectic alloy, perovskite films with large grain sizes up to 5 µm can be grown directly from liquid phase metal. Consequently, using an alloying technique and this unique growth mechanism, a less‐toxic and efficient perovskite solar cell with a power conversion efficiency (PCE) of 14.04% is demonstrated, while pure Sn and Pb perovskite solar cells prepared in this manner yield PCEs of 4.62% and 14.21%, respectively. It is found that this alloying technique can open up a new direction to further explore different alloy systems (binary or ternary alloys) with even lower melting point.     

Effect of lead on formation and dielectric tunability of (Pbx,Sr1? x )0.85Bi0.1TiO3 thin films

(Pb_x,Sr_1−x )_0.85Bi_0.1TiO₃ thin films with the perovskite phase structure were prepared on an ITO glass substrate by sol-gel method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and an impedance analyzer were respectively used in order to characterize the phase status, morphology and dielectric properties of the thin films. The results show that during the formation process of (Pb_x,Sr_1−x )_0.85Bi_0.1TiO₃ thin films, the nucleus of the perovskite phase are initially formed and then congregated. These aggregated nucleus are then transformed as the perovskite-phase crystalline in the thin film. Finally, the crystalline phase grows and separates gradually to form the perfect crystalline-phase structure. The content of the perovskite phase formed in the thin film under rapid thermal process (RTP) is more than that formed under traditional heat treatment with kinetic equilibrium. This is due to the high active decomposed ions that form the perovskite phase directly when heat-treated by RTP. The formation of the perovskite phase therefore overcomes a much lower barrier under RTP than that under traditional calcinations. The structure of the perovskite phase has a close relation to the ratio of Pb/Sr in the system because of the radius difference between Pb²⁺ and Sr²⁺. The transformation temperature between the cubic and the tetragonal structures of the perovskite phase increases with increasing Pb²⁺ content because the radius of Pb²⁺ is larger than that of Sr²⁺. It appears at room temperature when the content of Pb²⁺/Sr²⁺ is about 40/60 in the thin film. Meanwhile, the tetragonality of the perovskite phase is increased when Pb²⁺ ions increase due to its high polarization. The higher tunability of the (Pb_x,Sr_1−x )_0.85Bi_0.1TiO₃ thin film is exhibited when the film composition is close to the transformation point between the paraelectric and ferroelectric phases. Pb²⁺ ions show a dominant factor to affect the Curie point of the system and then changing tunability. Translated from Journal of Inorganic Materials, 2006, 21(2): 466–472 [译自: 无机材料学报]     

Transmission electron microscope study of the topotactic reaction of (0 0 1), (0 1 1) and (1 1 1) Ag films and Te

The formation, structure and morphology of silver telluride was investigated in the reaction of (0 0 1), (0 1 1) and (1 1 1) single crystalline Ag films with vacuum deposited Te. Silver films 30–40 nm in thickness were deposited by thermal evaporation onto water- and chlorine-treated NaCl. Onto this silver 1–40 nm of tellurium were deposited at 100 and 200 °C. The Ag–Te reaction occurred during Te deposition. Accordingly, formation of the compound phase was investigated from the nucleation stage through complete tellurization on either side of the polymorphic phase transformation temperature (T_c=150 °C). Transmission electron microscope and selected area electron diffraction showed that monoclinic silver telluride (Ag₂Te) of different morphology and texture was always formed. The orientation of silver and monoclinic phase upon differently oriented monocrystalline Ag films and at deposition temperatures around T_c is discussed.