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1.
Abstract Spin coated Pb1?xLaxTi1?x/4Q3 thin films (x ' 0.00, 0.05.…0.30) on (0001) sapphire were studied using x-ray diffraction, atomic force microscopy, and Raman scattering in order to investigate the phase formation, surface morphology, and the phase transition behavior in them. The x-ray and Raman scattering reveal a decrease in tetragonality with La substitution in lead titanate. Microscopy estimated surface roughness was also found to be decreasing with the La doping. Raman scattering, in the temperature range 75–783K, shows the transition temperature about 730, 680, 614, and 563 K for x'0.05, 0.10, 0.15, and 0.20 compositions, respectively. The diffuse nature of the ferroelectric phase transition owing to a short-range structural disorder in the paraelectric cubic phase and an increase in the diffuseness with La doping indicates the relaxor behavior and its relationship with the local disorder in these materials. 相似文献
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Noboru Yoshimura Masashi Itoi Shigeki Sato Haruo Taguchi 《Electrical Engineering in Japan》1992,112(5):10-16
A TiO2 thin film was prepared by the sol-gel method using a metal alkoxide [Ti(O-i-Pr)4 tetrasopropoxy titanium: TIPT]. The crystalline form of the film depends on the preparation conditions and the heat treatment temperature. When the ratio (γ) of H2O to TIPT is 7, the crystalline phase is formed at 400°C; when γ = 2 it is formed at 500°C. The anatase crystal structure was obtained for both γ = 2 and γ = 7. The electrical conductivity of the TiO2 film increased with the heat treatment temperature. 相似文献
4.
Takaaki Suzuki Toshihide Nabatame Kazutoshi Higashiyama 《Electrical Engineering in Japan》1999,129(4):1-6
SrBi2Ta2O9 thin films were successfully prepared at a low annealing temperature using a low-oxygen-concentration annealing technique. It was possible to obtain a single perovskite phase at 600 °C in 0.7% oxygen concentration and fluorite phase was observed at 600 °C in 100% oxygen. In addition, the SrBi2Ta2O9 thin films annealed at 650 °C in 0.7% oxygen were well crystallized and composed of dense crystal grains with a size of 70 nm. The remanent polarization and leakage current density of the SrBi2Ta2O9 thin film obtained using this new technique were 7 μC/cm2 and 3 × 10−9 A/cm2 (at 5 V), respectively. The final remanent polarization after 109 switching cycles was nearly constant. © 1999 Scripta Technica, Electr Eng Jpn, 129(4): 1–6, 1999 相似文献
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Yasuyuki Ito Maho Ushikubo Seiichi Yokoyama Hironori Matsunaga Tsutomu Atsuki Tadashi Yonezawa Katsumi Ogi 《Electrical Engineering in Japan》1997,120(2):27-33
A new low-temperature processing method to prepare SrBi2Ta2O9 thin films is proposed. These thin films were prepared on Pt/Ta/SiO2/Si substrates by a sol-gel method, and their structural and electrical properties were investigated. Films were annealed before and after the top Pt electrode deposition. The first annealing was performed in a 760-Torr oxygen atmosphere at 600 °C for 30 min, and the second annealing was performed in a 5-Torr oxygen atmosphere at 600 °C for 30 min. The films were well crystallized and fine-grained after the second annealing. The electrical characteristics of the 200-nm-thick film obtained by this new process were as follows: remanent polarization, Pr = 8.5 μC/cm2; coercive field, Ec = 36 kV/cm; and leakage current density, IL = 1 × 10−7 A/cm2 (at 150 kV/cm). This process is very attractive for highly integrated ferroelectric nonvolatile memory applications. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 120(2): 27–33, 1997 相似文献
6.
Highly ordered mesoporous TiO2 thin films have been successfully synthesized via a copolymer templating sol-gel route. A configuration transition from hexagonal,
to cubic, and then to a channel-like structure was observed when the copolymer-templated thin film was thermally annealed
from 110 to 450∘C. In the mesoporous TiO2 film annealed at 450∘C, mesopores were merged in a preferential direction, forming a channel-like structure consisting of a semicrystalline (anatase)
framework. These films exhibit excellent optical transparency with transmittance higher than 85% in the visible region. A
blue shift in UV-Vis absorption onset was shown for the mesoporous TiO2 films, indicating a size quantization effect of nanocrystalline titania. 相似文献
7.
Abstract The growth, microstructure and micro-Raman properties of SrBi2Tao0.8Nb1.2O9 (SBTN) thin films deposited on Si(100) substrates using pulsed laser deposition (PLD) technique were studied at various substrate temperatures. Films were characterized using X-ray diffraction(XRD), atomic force microscopy(AFM), energy dispersive X-ray analysis (EDAX) and micro-Raman studies. AFM studies indicated that the average grain size of the films increased between 0.08 μm to 0.1 μm with the increasing growth temperatures. Micro-Raman studies of SBTN films revealed the fact that shifting of Raman modes corresponds to the BO6 (where B' Ta/Nb) octahedral symmetry, to higher frequencies, is in accordance with the different masses of the B site atoms and the force constants involved due to Nb doping at Ta sites. 相似文献
8.
Abstract Ferroelectric PZT/PLZT thin films have been fabricated using the metallo-organic precursor compounds. The structural development, spectroscopic and dielectric properties of these films have been investigated using atomic force microscopy (AFM), X-ray diffraction, Raman scattering and dielectric measurements. Experimental results show that Raman spectroscopy is an effective tool of monitoring the structural development of the small sized PZT films in the tetragonal phase field. Dielectric characteristics have been improved by the rapid thermal processing approach. A rosette growth model is proposed to explain the observation of the tri-intersection of the perovskite phase in PZT films. 相似文献
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主要研究载体中有TiO2光催化剂存在时,去除烟气中NOx的4种技术,包括在TiO2表面上NH3和NO的光催化反应、Ru/TiO2催化剂在低温下对CO-NO的催化反应、Pt/TiO2催化剂去除NOx和TiO2-AC-Fe2O3催化剂去除低浓度NOx。研究TiO2的光催化机理及上述4种技术脱除NOx的机理。比较上述4种TiO2光催化脱氮技术现状及特点,提出基于TiO2光催化同时脱硫脱氮的技术展望。 相似文献
10.
Abstract Excimer laser annealing is a promising method for the crystallisation of ferroelectric layers, such as PZT, in low thermal budget integrated device fabrication processes. A technique is described whereby the problem of very high surface temperatures in PZT is overcome by the use of temporal pulse extension, where the effective laser pulse length is increased from 24ns to 374ns. Modelled temperature profiles through a PZT thin film structure during laser irradiation illustrate the benefit of pulse extension due to enhanced heat propagation into the PZT. The modelling also shows that underlying silicon is not heated significantly even with pulse extension. Initial results show that PZT can be crystallised into the perovskite phase from the top downwards with minimal surface damage. 相似文献
11.
Abstract Thin TiO2 layers were sputter-deposited on Pt/Ti/SiO2/Si wafers, as buffer layers for PZT thin film capacitors. It was found that TiO2 buffers of less than 4-nm-thickness could assist in obtaining highly uniform PZT thin films with no second phase. The leakage current behaviors of the PZT based capacitor are improved, while retaining the ferroelectric properties of PZT thin films such as remanent polarization and coercive field. In addition, the uniform distribution of oxygen in PZT on TiO2/Pt indicates that the TiO2 buffer layer act as a barrier for lead-platinum reaction, as well as for oxygen diffusion. 相似文献
12.
Jia Li Jin-Hua Huang Yu-Long Zhang Ye Yang Wei-Jie Song Xiao-Min Li 《Journal of Electroceramics》2011,26(1-4):84-89
We studied the effects of rapid thermal annealing in different ambients on the structural, electrical and optical properties of the sol-gel derived ZnO thin films. All the films after annealing showed highly degree of (002) oriented in the X-ray diffractometry (XRD) patterns. The effects of annealing ambients on electrical properties of the films were studied. Carrier concentration, resistivity and mobility were found to be distinguished after annealed in different ambients. The sample with the lowest resistivity of 0.095 ??·cm and the largest mobility of 105.1 cm2/v·s was achieved after annealing in vacuum. XPS results indicated that more oxygen vacancies existed on the ZnO surface when annealed in vacuum than that in O2. 相似文献
13.
Tae Sik Cho Min-Su Yi Ji Wook Jeung Do Young Noh Jin Woo Kim Jung Ho Je 《Journal of Electroceramics》2006,17(2-4):231-234
The sapphire orientation dependence of the microstructure of ZnO thin films has been studied in real-time synchrotron X-ray scattering experiments. The ZnO films with a 2400-Å-thick were grown on sapphire (001) and sapphire (110) substrates at room temperature by radio frequency magnetron sputtering. The as-deposited ZnO film on sapphire (001) has the only (002) crystal grains, while that on sapphire (110) has not only (002) crystal grains but (100) and (101) additional grains. The ZnO films were changed into fully epitaxial ZnO (002) grains both on sapphire (001) and sapphire (110) substrates with increasing the annealing temperature to 600°C. The epitaxial relationships of the ZnO grains were summarized as ZnO (00l)[100]//sapphire (00l)[110] and ZnO (00l)[110]//sapphire (110)[001]. 相似文献
14.
Tao Yu Dong-Sheng Wang Di Wu Ai-Dong Li Xin-Hua Zhu An Hu 《Integrated ferroelectrics》2013,141(1-4):333-339
Abstract Ferroelectric SrBi2Ta2O9(SBT) thin films prepared by metalorganic decomposition (MOD) method were annealed in forming gas (5% hydrogen + 95% nitrogen) at different temperatures for 60 min. SEM analysis results showed that an amount of columnar structures appeared on SBT surface when the annealing temperature was up to 450°C. When the annealing temperature raised up to 500°C, these columnar structures grew along one dimension and changed into wire structures. The EDX micro-area mapping analysis result showed that Bi was concentrated in the columnar or wire structures on SBT surface. The ferroelectric property analysis results showed that the hysteresis loops still existed after 5 min forming gas processing (350°C or 400°C), but when the annealing time was longer than 10 min, the resistance of the SBT samples became too low to measure the hysteresis loops. 相似文献
15.
Jin Young Kim Hyun Suk Jung Jung Hong No Jeong-Ryeol Kim Kug Sun Hong 《Journal of Electroceramics》2006,16(4):447-451
The phase transformation behavior and resulting dielectric properties of sol-gel derived TiO2 thin films were investigated. Thin films showed a typical behavior of mixture systems during the phase transformation; a
kinetic investigation on the isothermal curve of pre-crystallized thin films revealed that the phase transformation was a
first-order reaction with an Avrami time component of 1. Dielectric constants of TiO2 thin films increased with the increasing amount of the rutile phase while the dielectric losses showed the opposite relationship.
From a fitting process using the parallel mixing rule, dielectric constants of two end members of the mixture system were
calculated to be 41.4 and 145.2 for the pure anatase and rutile phase thin films, respectively. 相似文献
16.
真空热蒸发制备ZnS薄膜及其特性的研究 总被引:2,自引:0,他引:2
用真空热蒸发在不同衬底温度下制备了ZnS薄膜,利用X射线衍射(XRD)、X射线能谱(EDAX)、紫外可见分光光度计(UV-vis)和原子力显微镜(AFM)研究了ZnS薄膜的晶体结构、成分、光学性能和形貌,分析了衬底温度对ZnS薄膜结构与光学特性的影响。结果表明,所制备的ZnS薄膜呈立方闪锌矿结构,衬底温度为300℃所制备的ZnS薄膜原子比(S/Zn)为0.95/1;薄膜表面均匀致密,呈多晶态,晶粒尺寸为18.2nm;在可见区有好的透射性能,光学禁带宽度为3.82eV。 相似文献
17.
Abstract We have performed depth profile studies on PZT films of different thickness. Thin epitaxial films of PbZr0.2Ti0.8O3 have been deposited on mono-crystalline (001) LaAlO3 substrate by pulsed laser deposition. Grazing incidence X-ray scattering was used to study the films' structure. GIXS technique was used to analyze the in-plane compression of lattice parameters as a function of depth within the films. 相似文献
18.
以壳聚糖、聚乙烯吡咯烷酮(PVP)、醋酸锂和醋酸锰等为原料,采用溶胶凝胶-旋转涂布法在不锈钢基底上制备了LiMn2O4薄膜。通过X射线衍射光谱法(XRD)和扫描电子显微镜法(SEM)研究了退火温度对LiMn2O4薄膜的结构和形貌的影响,并研究了其电化学性能。结果表明:退火温度对薄膜的结构、形貌及电化学性能影响显著。在500~750℃下退火所制得的薄膜表面都呈现褶皱状的微观形貌,650℃以下退火的薄膜样品表面均匀致密,无裂痕。薄膜颗粒粒径随着温度的升高显著增大,结晶化程度也随之提高。650℃退火的薄膜样品为纯相尖晶石结构的LiMn2O4,并且具有最好的电化学性能,在50mA/cm2的电流下,初始比容量为35.9mAh/cm2·mm,经20次循环后比容量为33.8mAh/cm2·mm,容量保持了93.6%,表现出良好的循环性能。 相似文献
19.
On-site fabrication of ceramics films from solution precursors by ink-jet and spray assisted processes 总被引:1,自引:0,他引:1
Atsushi Matsuo Ruwan Gallage Takeshi Fujiwara Tomoaki Watanabe Masahiro Yoshimura 《Journal of Electroceramics》2006,16(4):533-536
Solution processing based on Ink-jet and spray technologies is one of low cost on-site ceramic patterns/films fabrication
methods at moderate temperatures from precursor solutions. In the present study, we have used ink-jet and spray technologies
to fabricate ceramic films of titania directly on glass substrates at 300–400∘C. The precursor solution was prepared by dissolving Titanium tetraisopropoxide in appropriate solvents (water/ethanol and
acetylacetone). A cleaned glass substrate was kept on a hot plate and heated it up to a predetermined temperature. Droplets
of the precursor solution produced through a spray gun were traveled towards heated substrate with a atmospheric pressure.
When the droplets hit on the heated substrate, precursor started to decompose, nucleate and grow into the TiO2 film. The anatase pattern was directly obtained by ink-jet method at moderate temperatures. 相似文献
20.
W-Ping Xu Lirong Zheng Chenglu Lin Masanori Okuyama 《Integrated ferroelectrics》2013,141(2-4):233-239
Abstract Barium titanate (BaTiO3) thin films with high (111)-orientation were successfully grown on TiO2-covered Si(111) substrate using hydrothermal method, where the TiO2 layer was previously fabricated at room temperature by means of ion-beam-assisted deposition. This processing method provides a simple mild-chemical route for directly producing the analogous crystalline films on different substrates. The BaTiO3 films did not reach the TiO2/Si interface even if the hydrothermal treatment was prolonged to 24 hours. Both Rutherford backscattering and spread-resistance profiling characterizations confirmed the diffusion nature of the formed Ba-TiO3/TiO2/Si system. 相似文献