LiCl/SiO2薄膜的制备及湿敏性能

采用溶胶－凝胶工艺,制备了ＬｉＣｌ／ＳｉＯ２多孔薄膜湿敏薄材料,薄膜采用提拉法在氧化铝基片上制成,用ＳＥＭ技术对薄膜的孔结构和表面形貌进行了观察,用ＸＲＤ技术研究了热处理温度对ＬｉＣｌ／ＳｉＯ２凝胶结晶行为的影响,研究了ＬｉＣｌ／ＳｉＯ２薄湿敏特性。     

利用表面形成Si_2N_2O层提高Si_3N_4陶瓷材料抗氧化性能

根据对Ｓｉ－Ｎ－Ｏ系统相图的分析，首次在Ｓｉ３Ｎ４陶瓷材料表面形成Ｓｉ２Ｎ２Ｏ抗氧化层。其方法是利用Ｓｏｌ－Ｇｅｌ在Ｓｉ３Ｎ４陶瓷的表面涂上一层ＳｉＯ２（其中含有１０％的Ａｉ２Ｏ３）涂层后，在Ｎ２气氛中，并有Ｓｉ３Ｎ４粉末和ＳｉＯ２粉末存在的条件下，于１２７３～１６７３Ｋ的温度下进行热处理。用ＸＲＤ和ＸＰＳ分析验证了Ｓｉ２Ｎ２Ｏ（和／或Ｏ’－Ｓｉａｌｏｎ）层的存在。由于形成了Ｓｉ２Ｎ２Ｏ（和／或Ｏ’－Ｓｉａｌｏｎ）层，Ｓｉ３Ｎ４陶瓷材料在１５７３Ｋ的温度下氧化１００ｈ后，氧化增量从原来的０．４２ｍｇ／ｃｍ２降低到０．２４ｍｇ／ｃｍ２。     

涂敷型铬酸盐钝化膜的结构与耐蚀性

采用ＳＲＤ，ＥＤＸＡ，ＧＤＳ等方法研究了镀锌钢板表面涂敷型ＣｒＯ３－Ｈ３ＰＯ４－ＳｉＯ２系钝化膜的成分与结构。该钝化膜是一种由ＣｒＯ３，Ｃｒ（ＯＨ）３，ＣｒＯＯＨ，ＺｎＣｒＯ４，ＺｎＳｉＯ３，Ｚｎ３（ＰＯ４）２，ＣｒＰＯ４和ＳｉＯ２组成的凝胶网络状结构的涂敷型复合转化膜。探讨了其耐蚀机理，中性盐雾试验表明：该钝化膜的耐蚀性大大优于ＣｒＯ３－ＳｉＯ２系钝化膜。     

KTa0.55Nb0.45O3薄膜的介电和铁电及热释电性能研究

在ＢＴ／Ｐｔ／Ｔｉ／ＳｉＯ２／Ｓｉ衬底上用溶胶－凝胶法制备了ＫＴａ０．５５Ｎｂ０．４５Ｏ３（ＫＴＮ）薄膜,０．５μｍＫＴＮ－０．０８μｍＢＴ薄膜在２５℃,１．０ｋＨｚ时,其εｒ＝１１１４,ｔａｎδ＝２．５％;１２℃时,其中Ｐｒ＝２．１μＣ／ｃｍ＾２,Ｐｓ＝４．２μｃ／ｃｍ＾２,Ｅｃ＝５．８ｋＶ／ｃｍ,０．５μｍ厚ＫＴＮ膜的Ｃｕｒｉｅ温度为３５℃;１．０ＫＨｚ时,ＫＴＮ膜的εｒ＝１４１２,估算ＫＴＮ     

聚合物基纤维纳米复合材料研究

以纳米粒子ＳｉＯ２－ｘ、高强玻璃纤维（Ｓ－ＧＦ）作为增强材料,分别以环氧树脂ＣＹＤ－１２８和４,４－二氨基二苯基砜（Ｄ－ＤＳ）作为基体中制备了聚合物基纤维纳米复合材料,测试了预浸料及复合材料的性能。结果表明,Ｓ－ＧＦ、ＳｉＯ２＝ｘ／ＣＹＤ＝１２８／ＤＤＳ与Ｓ－ＧＦ／ＣＹＤ－１２８／ＤＤＳ两种体系预浸料性能相似,但ＳｉＯ２－ｘ纳米粒子的加入,使复合材料的各项性能提高。     

Sol—gel法制备纳米硅碳膜的研究

以长链甲基三甲氧基硅烷〖ＣｎＨ２ｎ＋１Ｓｉ（ＯＣＨ３）〗和正硅酸惭脂（ＴＥＯＳ）身份种有机物为起始原料,用溶胶－产胶法制备也ＳｉＣ膜。初步讨论了溶胶形成过程中水中氢键、酸及碱的作用。利用Ｒａｍａｎ光谱和透射电镜（ＴＥＭ）结合ＸＰＳ等测试方法对制得的膜进行了结构、颗粒尺寸及化学成分等的研究,根据分析和观察结果,膜由颗凿及寸在直径为２ｎｍ－４ｎｍ,长度为２０ｎｍ－４０ｎｍ左右的ＳｉＣ纳米晶须构成,纯度     

纳米TiO2／Si薄膜的制备与光催化性能的研究

纳米ＴｉＯ２／Ｓｉ薄膜的制备与光催化性能的研究符小荣１，＊宋世庚１，２王学燕１谭辉１武光明１陶明德１（１中科院新疆物理所，乌鲁木齐８３００１１）（２中科院上海冶金所信息功能材料国家重点实验室，上海２０００５０）关键词ＴｉＯ２，光催化，薄膜，溶胶－凝胶...     

AlN／SiCw（Y2O3＋SiO2）复合材料热处理增强研究

研究了热处理对ＡｌＮ／ＳｉＣｗ（Ｙ２Ｏ３＋ＳｉＯ２）复合材料机械性能的影响。结果表明，该材料经热处理后的强度提高，当添加剂Ｙ２Ｏ３／ＳｉＯ２＝１／２．５摩尔比时，提高幅度最大。经ＸＲＤ，ＳＥＭ，ＴＥＭ／ＥＤＡＸ和ＨＲＥＭ分析，热处理增强的机理主要是粒界玻璃相在高温氧化气氛中和ＡｌＮ颗粒表层作用，生成的纤维２Ｈ＾δＳｉａｌｏｎ相和ＳｉＣｗ形成空间交错结构。     

用金属有机化合物制备铁电薄膜：工艺及进展

本文概述了以金属有机化合物为原料制备铁电薄膜的工艺过程、工艺特点及最新研究进展，着重介绍了金属有机物化学气相溶积（ＭＯＣＶＤ），金属有机物热分解（ＭＯＤ）以及溶胶－凝胶（Ｓｏｌ－Ｇｅｌ）三种制备技术在铁电薄膜制备领域中的应用。     

Si3N4陶瓷材料的氧化行为及其抗氧化研究

研究了Ｓｉ３Ｎ４陶瓷材料的氧化行为,同时探讨了通过表面处理使Ｓｉ３Ｎ４陶瓷材料表面形成一层Ｓｉ２Ｎ２Ｏ对其抗氧化性能的影响。实验结果表明,Ｓｉ３Ｎ４陶瓷材料在空气中的氧化行为服从抛物线规律。另外,用Ｘ射线衍射分析（ＸＲＤ）和Ｘ光电子能谱（ＸＰＳ）分析验证了Ｓｉ２Ｎ２Ｏ层的存在。由于形成了Ｓｉ２Ｎ２Ｏ层,Ｓi３Ｎ４陶瓷材 在１３００℃下氧化１００h后,氧化增重从原来的０．４２ｍｇ／ｃｍ＾２降低到０．２     

Recent Materials Characterizations of [2D] and [3D] Thin Film Ferroelectric Structures

A review is given of ceramic and single-crystal thin film ferroelectric oxides, emphasizing perovskite phases, together with some new developments on hafnia films. It is shown that single-crystal barium titanate films behave as bulk down to at least 77 nm, with no finite size effects, no phase transition temperature shifts, and no dielectric peak broadening or change from first- to second-order transitions, suggesting that the gradient defect model of Bratkovsky and Levanyuk correctly describes such effects as extrinsic in experimental studies of equally thin ceramic thin films. In ceramic barium–strontium titanate (BST) thin films, it is shown that there is also no intrinsic broadening or shifts in phase transitions, with sharp, unshifted, bulk-like transitions observed only as re-entrant upon warming from cryogenic temperatures; this shows that phase transitions in ceramic thin films are dominated by kinetics and not thermodynamics and are definitely not equilibrium measurements. At high fields (>1 GV/m), the films exhibit space charge-limited conduction; no variable-range hopping is observed, contrary to recent studies on SrTiO₃. Some novel, unconventional switching processes are discussed, comparing the "perimeter effect" (non-equilibrium, ballistic) with Molotskii's equilibrium model. Theory and experiment are described for [3D] nanotubes, nanorods, and nano-ribbons (or micro-ribbons). The layered-structure-perovskite–pyrochlore conversion in bismuth titanate is described together with the PbO+TiO₂ phase separation in lead zirconate titanate during electrical breakdown, as are novel HfO₂ precursors that demonstrate enhanced temperature crystallization from the amorphous state and hence commercial advantages for front-end processing.     

Influence of strain on the dielectric properties of Bi–Zn–Ti–Nb–O solid solution thin films

Bi–Zn–Ti–Nb–O (BZTN) solid solution thin films with various compositions were prepared by metalorganic decomposition (MOD) process on the platinized Si substrates. BZTN thin films showed a wide solid solubility since the thin films maintained the single phase of cubic pyrochlore structure in a broad range of composition. Crystal structure and dielectric properties of BZTN thin films were compared to those of BZTN bulk ceramics and the difference in dielectric properties such as dielectric constant, dielectric loss and tunability between thin films and bulk ceramics were understood to originate from the strain in the thin films since there was no apparent difference in the other factors such as microstructure and preferred orientation. The existence of strain in the thin films was confirmed by two ways. One is the rate of lattice shrinking. Shrinkage in the lattice parameter of thin films was depressed compared to that of bulk ceramics, which might introduce the internal strain in the thin films. Another is the thermal expansion coefficient (α, TEC) of BZTN solid solutions. TEC measured from the bulk ceramics varied with composition and the difference in the TEC between the polycrystalline thin film and underlying substrate would result in the thermal strain of thin films. Thin films with various compositions were under different degree of tensile stress state and the BZTN thin films with optimal composition demonstrated the high tunability of 30% under 1100 kV/cm with dielectric constant of 242 and dielectric loss of 0.004.     

Structural phase transition,electrical and photoluminescent properties of Pr3+-doped (1-x)Na0.5Bi0.5TiO3-xSrTiO3 lead-free ferroelectric thin films

Lead-free ferroelectric Pr³⁺-doped (1-x)Na_0.5Bi_0.5TiO₃-xSrTiO₃ (x?=?0–0.5) (hereafter abbreviated as Pr-NBT-xSTO) thin films were prepared on Pt/Ti/SiO₂/Si and fused silica substrates by a chemical solution deposition method combined with a rapid thermal annealing process at 700?°C, and their structural phase transition, dielectric, ferroelectric, and photoluminescent properties were investigated as a function of STO content. Raman analysis shows that with increasing STO content, the phase structures evolve from rhombohedral phase to coexistence of rhombohedral and tetragonal phases (i.e. morphotropic phase boundary), and then to tetragonal phase. The structural phase transition behavior has been well confirmed by temperature- and frequency- dependent dielectric measurements. Meanwhile, the variation in photoluminescence intensity of Pr³⁺ ions with different STO content in the NBT-xSTO thin films also indicates that there exists a clear structural phase transition when the film composition is close to the morphotropic phase boundary. Superior dielectric and ferroelectric properties are obtained in the Pr-NBT-0.24STO thin films due to the formation of morphotropic phase boundary. Our study suggests that Pr-NBT-xSTO thin films be promising multifunctional materials for optoelectronic device applications.     

自组装聚电解质薄膜的低角度X射线衍射研究

采用静电自组装技术在单晶硅和石英玻璃基片上制备了阳离子聚电解质PDDA和阴离子聚电解质PS-119的多层复合薄膜,对薄膜作低角度X射线衍射分析,得到清晰的Kiessig衍射曲线,根据衍射曲线估算了薄膜的厚度。自组装PDDA/PS-119薄膜的层状结构特征不明显,聚电解质单层的厚度可以控制在1nm上下,双层的厚度可以控制在2nm左右,薄膜的总厚度与聚电解质水溶液的浓度有关,与薄膜的双层数成比例关系。     

溶胶-凝胶法制备钛酸锶钡铁电薄膜的研究

钛酸锶钡(BST)薄膜是一类重要的铁电薄膜材料。采用溶胶-凝胶法制备了不同组分的具有钙钛矿结构的BST薄膜。利用X射线衍射技术(XRD),研究了不同退火条件下BST薄膜的结晶特性,结果表明制备的BST薄膜形成了单一的钙钛矿结构;利用扫描电子显微镜(SEM)和原子力显微镜(AFM)观察了薄膜的表面形貌,结果表明制备的BST薄膜光滑,平整,无明显的孔洞和裂纹,且生长良好。BST薄膜的晶粒细致,排列整齐,分布均匀,呈现球状。     

Ba(Zr0.3Ti0.7)O3薄膜的结构及性能

用溶胶-凝胶法分别在Pt/Ti/SiO2/Si和LaNiO3/Pt/Ti/SiO2/Si衬底上制备了锆钛酸钡[Ba(Zr0.3Ti0.7)O3,BZT]薄膜.相结构及介电性能研究表明:衬底和薄膜厚度对BZT薄膜性能具有显著影响.制备在LaNiO3/Pt/Ti/SiO2/Si衬底上的BZT薄膜具有(100)面的择优取向,其介电常数及介电损耗则随着薄膜厚度的增加而降低.对制备在Pt/Ti/SiO2/Si衬底上的BZT薄膜,在薄膜厚度低于500nm时,其介电常数随薄膜厚度增加而增加,大于500nm时又有所减小.     

Model silica-alumina acid catalysts for surface science and catalysis studies prepared by argon ion beam sputter deposition using HY-zeolite targets

Thin films of silica-alumina were prepared by argon ion beam sputter deposition on gold foil using different HY-zeolites as targets. X-ray photoelectron spectroscopy (XPS) results on thin films (< 10 nm) revealed that the Si/Al ratio in the films initially decreases with deposition time, but later becomes very similar to that of the target zeolite. Similarly, the position of O 1s, Al 2p, Si 2p peaks converged to the binding energies for zeolite target used. Based on the line shape of the O KVV Auger transition, we find that there is no segregation of silica and alumina in the films. By scanning electron microscopy (SEM) and scanning Auger electron spectroscopy (SAE) the thin films appear homogeneous. X-ray diffraction (XRD) results on thicker films ( 1 m) indicate that the silica-alumina layers are amorphous.To test the catalytic activity cumene cracking was performed in a glass reactor. The sputter deposited thin silica-alumina films were active in cumene cracking at 573 K but at least a total of 20 cm² macroscopic surface area was needed to easily distinguish the activity of the film from the background activity. Similar thin films prepared from alumina or silica or the a mixture of the two were inactive. Thus, the sputtered thin film retains some chemical memory of the target.     

ZrO_2溅射膜的柱状生长机制

气相沉积ZrO2 膜常为柱状结构 ,要更好地控制ZrO2 膜性能 ,需要研究ZrO2 膜中柱状结构的形成和演化规律 .在射频溅射条件下沉积了ZrO2 膜 ,发现该膜的柱状晶具有 { 111}面织构 ,其底层可能还有等轴晶 .提出以下柱状晶形成机制 :在光滑 (玻璃 )基片上形成的柱状晶源自于在基片表面形成的具有 { 111}面织构的最初晶核 ;在较为粗糙 (多晶Al2 O3)基片表面上形成的柱状晶源自于〈111〉晶向与沉积物质流方向一致的晶核择优生长及随后对其它取向的小晶核的吞噬而形成的晶核群 .基片表面粗糙时 ,由于柱状晶核经过晶核筛选产生 ,柱状晶底部可能有等轴晶层 ;若温度较低 ,出现等轴晶层可能性更大     

不同金属离子掺杂TiO2薄膜的制备及光催化活性的研究

以溶胶-凝胶法制备了分别用Ag^+、Cu²⁺、Fe³⁺、La³⁺、Ce³⁺和Eu³⁺等离子掺杂的纳米TiO₂薄膜，经XRD和UV-Vis对薄膜样品进行表征并研究了其光催化活性。XRD结果证明，掺镧TiO₂薄膜与未掺杂薄膜的X射线衍射图基本一致，实验条件下主要为锐钛矿型，且掺入La^3+离子使得TiO₂薄膜的晶粒变小。UV-Vis吸收光谱说明当λ＞380 nm时，其吸光度低于0.15。薄膜光催化降解亚甲基蓝的实验表明,La³⁺或Fe^3+掺杂薄膜的光催化降解率远高于未掺杂TiO₂薄膜，而Ce^3+或Cu^2+离子掺杂薄膜与未掺杂薄膜的光催化活性相似，掺Ag⁺或Eu³⁺离子则降低了活性。当最佳掺杂量La³⁺为0.6%或Fe³⁺为1.5%时，光催化降解率分别高达92%和82%。     

Pulsed laser deposition of Sm modified PbTiO3 ferroelectric thin films

Sm modified PbTiO³ thin films have been prepared by pulsed laser deposition on Pt/TiO₂/SiO₂/(100)Si substrates. It has been found that the Sm concentration of the films remains close its concentration in the target, however, a Pb loss exists during the deposition process. To compensate for the Pb loss we used Pb rich targets and an oxygen pressure of 0.1 mbar. Films deposited at 530°C are crystalline and preferentially oriented with the [100] film direction perpendicular to the substrate surface. In comparison to bulk ceramics, the films have a tetragonal distortion lower than that expected from their Sm concentration. This is likely due to the influence of the substrate. The films prepared are ferroelectric with aP_r = 3.2 μC/cm².