MgO/Al2O3吸附剂对CO2静态吸附性能研究

采用等体积浸渍法制备MgO/Al2O3吸附剂。利用X光电子衍射(XRD)、氮气吸附、原位红外吸附等手段对材料的结构进行表征,通过静态吸附的方法对其吸附性能进行了测定。实验结果表明,所得到的MgO/Al2O3吸附剂,主要存在3个不同的碱性位,CO2吸附后主要是以碳酸氢盐、双齿碳酸盐和单齿碳酸盐的形式存在的。当MgO的负载量为10wt%时,其对CO2的吸附量是最大的。在30℃条件下,其对CO2的吸附量为54.1mg/g,随着温度的升高,吸附量有所降低,在100℃时,其对CO2的吸附量为31mg/g,吸附量的降低主要是由于碳酸盐的分解所致。     

Interpretation of dielectric properties of thin film Al/Al2O3/Au structures

On the basis of experimental data previously presented, the dielectric properties of thin film Al/Al₂O₃/Au structures were investigated in the frequency range 10^-2−10⁺⁵Hz. The results of the measurements suggested the existence of two laws of dispersion of the complex dielectric susceptibility, each obeying the empirical relation χ′(ω)∝χ≈(ω)∝ωⁿ⁻¹, with n = 0.14 in the low frequency range and n = 0.88 at higher frequencies. In this paper, an equivalent circuit is proposed; it takes into account, firstly, the two laws of dispersion which coexist over the whole temperature (393–505 K) and frequency ranges studied and, secondly, the existence of a thin interfacial zone at the electrode(s), which is less conducting than the bulk of the dielectric.     

Etch characteristics of TiN/Al2O3 thin film by using a Cl2/Ar adaptive coupled plasma

In this study, we carried out an investigation in the etching characteristics of TiN thin films in a C1₂/Ar adaptive coupled plasma. The maximum etch rate of the TiN thin films was 768 nm/min at a gas mixing ratio of C1₂ (75%)/Ar (25%). At the same time, the etch rate was measured as functions of the various etching parameters. The X-ray photoelectron spectroscopy analysis showed the efficient destruction of the oxide bonds by the ion bombardment as well as the accumulation of low volatile reaction products on the etched surface. Field emission Auger electron spectroscopy analysis was used to examine the efficiency of the ion-stimulated desorption of the reaction products.     

Al/Al2O3多层膜的研究

用真空蒸镀及自然氧化方法在玻璃基底上制备纳米量级的4、5、6、7对层的Al／Al2O3多层膜。采用称重法测定薄膜的厚度；在常温和低温下使用三点法测定多层膜的电特性；用扫描电镜（sEM）观察薄膜的表面和截面的形貌及成分。结果表明：制备的是纳米量级非晶态的Al／Al2O3多层膜，在常温和低温（77K）下均具有类似负阻的特性。     

Al2O3/TiO2 multilayer passivation layers grown at low temperature for flexible organic devices

In this study, the permeability of passivation layers consisting of aluminum oxide (Al2O3) and titanium oxide (TiO2) was examined. The films were deposited on poly(ether sulfone) (PES) substrates via electron cyclotron resonance atomic layer deposition (ECR-ALD) at various deposition temperatures. The optimum plasma power and deposition temperature were investigated through measurements of the refractive index and packing density of the Al2O3 and TiO2 films. A buffer layer/multilayer structure was proposed in this study to improve the passivation barrier performance. A low water vapor transmission rate (WVTR) of approximately 5 x 10(-3) g/m2 x day was achieved with two Al2O3/TiO2 stacks with thicknesses of 40 nm deposited at 80 degrees C. Based on the Arrhenius rate equation, the activation energy of water vapor transmission through different passivation structures was examined. The activation energies of Al2O3, Al2O3/TiO2, and two Al2O3/TiO2 stacks with thicknesses of 40 nm were 51.8, 63.9, and 74.7 kJ/mol, respectively.     

CdS/Nd2O3 and CdSe/Nd2O3 thin film transistors

Thin film transistors were grown by the multiple-pumpdown method of vacuum deposition. The behaviour of CdS and CdSe thin film transistors with Nd₂O₃ as the gate insulator was studied, and the various characteristics and parameters of the fabricated devices were determined. The performance of CdSe-Nd₂O₃ thin film transistors was found to be superior to that of CdS/Nd₂O₃ thin film transistors. The devices showed little change over a period of 4 months.     

High performance flexible organic thin film transistors (OTFTs) with octadecyltrichlorsilane/ Al2O3/poly(4-vinylphenol) multilayer insulators

The incorporation of a thin, atomic layer deposited Al2O3 layer in between a spin-coated poly-4-vinyl phenol (PVP) organic layer and octadecyltrichlorsilane (OTS) in the multilayer gate dielectric for pentacene organic thin film transistors on a n(+)-Si substrate reduced the gate leakage current and thereby significantly enhanced the current on/off ratio up to 2.8 x 10(6). Addition of the OTS monolayer on the UV-treated Al2O3 improved the crystallinity of the pentacene layer, where the OTS/UV-treated Al2O3 surfaces increased their contact angles to 100 degrees. X-ray diffraction (XRD) analysis revealed a more intense (001) crystal reflectance of pentacene deposited on OTS/UV-treated Al2O3 surface than that on OTS/Al2O3 surface. Moreover, the improved pentacene layer contributed to the field effect mobility (0.4 cm2/Vs) and subsequently improved the electrical performances of organic thin film transistor (OTFT) devices. This PVP/UV treated Al2O3/OTS multilayer gate dielectric stack was superior to those of the device with the single PVP gate dielectrics due to the improved crystallinity of pentacene.     

以Al2O3为过渡层脉冲激光法制备PZT铁电薄膜

为实现PZT铁电薄膜与半导体衬底的直接集成引入Al2O3为过渡层，首先用真空电子束蒸发法在Si(100)，多昌金刚石（111）衬底上生长约20nm厚的Al2O3过渡层，接着在上述衬底上采用脉冲激光淀积（PLD）法淀积PZT薄膜，衬底温度为350-550℃。X光电子能谱（XPS）测试表明，在高真空下，电子束蒸发Al2O3固态源能获得化学配比接近蒸发源的Al2O3薄膜。X射线衍射（XRD）测试说明，不论衬底是硅还是多晶金刚石，当衬底温度为550℃时，PZT在Al2O3过渡层上呈现（222）取向的焦绿石相结构，当衬底是金刚石时，通过如下工艺：（1）较低温度（350℃）淀积；（2）空气氛围650℃快速退火5min，可以在Al2O3过渡层上获得高度（101）取向的钙钛矿结构的铁电相PZT薄膜，最后AFM测试显示，在硅衬底上，PZT薄膜的表面均方根粗糙度为9.78nm；而在多晶金刚石衬底上，PZT薄膜的表面均方根粗糙度为17.2nm。     

Al2O3/SiO2／MgO复合纳米添加剂的抗磨减摩性能

采用超声机械法制备纳米Al2O3、SiO2、MgO等颗粒，并对其进行化学修饰，使其稳定地分散在基础油中，获得自修复纳米润滑添加剂。通过四球试验与止推圈试验考察摩擦学性能。试验结果表明：自修复纳米润滑添加剂具有良好的分散稳定性、抗磨减摩性和自修复性。     

提高钢基表面Al_2O_3薄膜结合力的研究

采用射频磁控溅射法在40Cr基体上制备了非晶态Al2O3薄膜,并研究了工艺参数(溅射功率,工作气压,溅射时间)、预处理工艺以及中间层对薄膜结合性能的影响。试验结果表明,采用射频溅射法,在功率为250W、工作气压为5.0Pa、时间为3h条件下制备的薄膜结合力最好。基体经过腐蚀预处理和加入镍磷中间层均能改善膜基结合力,后者效果更显著。     

In-situ high temperature X-ray diffraction study of Fe/Al2O3 interface reactions

In-situ experiments on the Fe/Al2O3 interface reaction were carried out with a high temperature X-ray diffractometer capable of measuring the X-ray diffraction pattern in 1–4s, using an imaging plate. The kinetic formation processes of the interface reaction layer were measured in short-period exposure experiments using the apparatus. The time-temperature phase diagram of Fe/Al2O3 in air was determined. Fe/Al2O4 was formed at the FeAl2O3 interface between 1595 K and 1675 K in air. The formation of FeAl2O4 obeyed the parabolic rate law. The value of the activation energy suggests that the diffusion of Al into FeAl2O4 controls the rate of formation. The results of thermal expansion coefficient measurements suggest that when a sample is cooled to room temperature, compressive strain caused by FeAl2O4 occurs on Al2O3.     

The interaction of Al,Ag, Au,and Ti to Pr2O3 thin film dielectrics

We studied the thermal stability of various electrode materials on 2 nm Pr₂O₃ dielectric films. Thin Al, Au, Ag, and Ti layers are deposited, by thermal evaporation or by sublimation (case of Ti). The Pr₂O₃ layers were deposited on Si substrates by electron beam evaporation from a Pr₆O₁₁ powder and by wet chemical deposition. XPS and SR-PES were used to study the effect of annealing on the metal to Pr₂O₃ interaction. XPS results show a strong diffusivity of Al, Ag, and Au in Pr₂O₃ upon annealing to 300 °C with formation of alloying with Si substrate. In contrast, Ti remained stable even upon annealing to 900 °C. SR-PES results show a stable Titanium oxides formation at room temperature. All results demonstrate that Ti is a good diffusion barrier between metal contacts and Pr₂O₃ or can be used as a metal contact.     

Subsolidus,high temperature phase relations in the systems Al2O3-Cr2O3-ZrO2, MgO-Cr2O3-ZrO2 and MgO-Al2O3-ZrO2

In the temperature range 1600 to 1900° C, the system A₂O₃-Cr₂O₃-ZrO₂ is characterized by the coexistence of ZrO₂ (unstablilized) and an (Al, Cr)₂O₃ solid solution series. In the systems MgO-Cr₂O₃-ZrO₂ and MgO-Al₂O₃-ZrO₂ a nearly stoichiometric spinel coexists with both stabilized and unstabilized ZrO₂. At temperatures above 1600°C a new ternary Mg-Al-Zr oxide becomes stable in the MgO-rich part of the MgO-Al₂O₃-ZrO₂ system.     

TiO2/ Al2O3复合薄膜的亲水性能研究

采用溶胶-凝胶法制备了TiO2／Al2O3复合薄膜，通过XRD、XPS、UV透射光谱的分析及薄膜表面接触角的测量，研究了Al2O3与TiO2配比、热处理温度、膜厚度等因素对复合膜的亲水性、透光率的影响。结果表明：Al2O3的加入和膜厚度的增加均有利于TiO2薄膜亲水性的改善；热处理温度对TiO2／Al2O3复合膜的亲水性有较大影响，其中经450℃热处理的薄膜亲水性最好；Al2O3的加入未降低复合膜的可见光透光率，其平均透光率大于80％。     

MgO/Eu2O3共掺杂对Al2O3陶瓷微波介电性能的影响

利用湿化学法制备了MgO/Eu₂O₃共掺Al₂O₃陶瓷, 研究了不同的MgO/Eu₂O₃掺杂量对Al₂O₃陶瓷物相组成、显微结构和微波介电性能的影响。结果表明: 适量的MgO/Eu₂O₃共掺有助于Al₂O₃的致密化和晶粒生长。在介电性能方面, MgO/Eu₂O₃共掺对Al₂O₃陶瓷的介电常数没有明显的影响, 但对介电损耗的影响显著。随着Eu₂O₃含量的增加, Al₂O₃陶瓷的Q×f值会呈现先增加后下降的变化趋势。0.05wt% MgO/0.10wt% Eu₂O₃共掺的样品在1590℃下保温4 h获得的微波介电性能最佳, ε_r~9.82, Q×f ~225, 225 GHz。Q×f值的这种变化可能与样品微观结构的变化相关。先是随着MgO/Eu₂O₃共掺量的增加, 晶粒尺寸不断增加, 晶界不断减少, 这有利于Q×f值的提高; 接着, 当MgO/Eu₂O₃共掺量进一步增加时, 晶粒尺寸不断下降, 晶界增多, 这会导致样品Q×f值的降低。另外, 应力和第二相也可能对Q×f值的变化产生影响。     

Electrical characteristics of SrxBi2.4Ta2O9 thin film and Pt/Sr0.85Bi2.4Ta2O9/Al2O3/Si structure

Sr _x Bi_2.4Ta₂O₉ (0.7 x 1.3) thin films were processed by metalorganic decomposition and their ferroelectric characteristics were investigated. The Sr-deficient Sr _x Bi_2.4Ta₂O₉ films exhibited well-developed ferroelectric hysteresis curves compared to those of the Sr-excess films, and Sr_0.85Bi_2.4Ta₂O₉ film had the optimum electrical characteristics among Sr _x Bi_2.4Ta₂O₉ films. Electrical characteristics of the Pt/SBT/Al₂O₃/Si structure using Sr_0.85Bi_2.4Ta₂O₉(SBT) film were investigated for metalferroelectric-insulator-semiconductor field-effect-transistor (MFIS-FET) applications. Memory window of C-V hysteresis characteristics of the Pt/SBT/Al₂O₃/Si structure became large with decreasing the Al₂O₃ thickness, and the Pt/SBT(400 nm)/Al₂O₃ (10 nm)/Si structure gave memory window of 2.2 V at sweeping voltages of ±5 V. The Pt/SBT/Al₂O₃/Si structure can be proposed for MFIS-FET applications.     

Low temperature silicon nitride by hot wire chemical vapour deposition for the use in impermeable thin film encapsulation on flexible substrates

High quality non porous silicon nitride layers were deposited by hot wire chemical vapour deposition at substrate temperatures lower than 110 degrees C. The layer properties were investigated using FTIR, reflection/transmission measurements and 1:6 buffered HF etching rate. A Si-H peak position of 2180 cm(-1) in the Fourier transform infrared absorption spectrum indicates a N/Si ratio around 1.2. Together with a refractive index of 1.97 at a wavelength of 632 nm and an extinction coefficient of 0.002 at 400 nm, this suggests that a transparent high density silicon nitride material has been made below 110 degrees C, which is compatible with polymer films and is expected to have a high impermeability. To confirm the compatibility with polymer films a silicon nitride layer was deposited on poly(glycidyl methacrylate) made by initiated chemical vapour deposition, resulting in a highly transparent double layer.     

The surface diffusion coefficients of MgO and Al2O3

From the measurement of neck size and neck curvature during the sintering of two spheres the surface diffusion coefficients of MgO and Al₂O₃ were determined. The spheres of both materials were machined from single crystals. The following values of surface diffusion coefficients were found: for MgO,D _{s s} = 3.7 × 10^–4 exp (407.8 kJ mol^–1/RT m³ sec^–1; for Al₂O₃,D _{s s} = 1.5 × 10^–2 exp (518.7 kJ mol^–1/RT) m³ sec^–1.     

Physical properties of slip casting of high pure Al2O3 slurry using porous Al2O3-glass mold

Physical properties of advanced ceramics are influenced by impurities produced in the forming process. The forming compacts produced by slip casting using gypsum molds contain calcium and sulfur in green bodies. Therefore, a porous Al₂O₃-glass mold was produced and slip casting was performed in the present study. Porous Al₂O₃ ceramics as casting molds were examined in comparison with gypsum mold from viewpoints of free energy for wettability and rate of filter cake buildup. The sintered compact of Al₂O₃ produced by slip casting using the porous Al₂O₃-glass mold was compared with those using the gypsum mold. Transmittance of the sintered Al₂O₃ compacts using the porous Al₂O₃-glass molds was increased in comparison with that using the gypsum mold.