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1.
Pb1- xLaxTiO3薄膜的制备及介电性质的研究   总被引:1,自引:0,他引:1  
在Pt/Ti/SiO2/Si(100)衬底上用溶胶-凝胶法制备了Pb1-xLaxTiO3薄膜,对膜进行XRD、SEM、介电、铁电性能测试,研究了退火温度、掺La量对薄膜性能的影响,结果发现在600℃下退火1h的PLT薄膜呈现钙钛矿结构,具有(100)面择优取向。在摩尔比x≤0.2的范围内,薄膜的矫顽场、剩余极化强度都随着掺La量的增加而降低,而其相对介电常数和介质损耗却随着掺La量的增加而增加。  相似文献   

2.
《功能材料》2001,32(2):124-125
用溶胶-凝胶法在Pt/Ti/SiO2/Si(100)基底上制备Pb1-xLaxTiO3(PLT,x≤0.2)薄膜,研究薄膜的结构及其介电、铁电性能.在600℃下退火1h的PLT薄膜表现出单一的钙钛矿结构,(100)择优取向明显.在室温下PLT薄膜有典型的电滞回线.在x≤0.2(摩尔比)的范围内,PLT薄膜的矫顽场、剩余极化强度都随着La的增加而降低,相对介电常数则随着La的增加而增加.  相似文献   

3.
用溶胶-凝胶法在Pt/Ti/SiO2/Si(100)基底上制备Pb1-xLaxTiO3(PLT,x≤0.2)薄膜,研究薄膜的结构及其介电、铁电性能。在600℃下退火1h的PLT薄膜表现出单一的钙钛矿结构,(100)择优取向明显。在室温下PLT薄膜有典型的电滞回线。在x≤0.2(摩尔比)的范围内,PLT薄膜的矫顽场、剩余极化强度都随着La的增加而降低,相对介电常数则随着La的增加而增加。  相似文献   

4.
Pb1-xLaxTiO3薄膜的制备及介电特性研究   总被引:1,自引:0,他引:1  
用溶胶-凝胶法在Pt/Ti/SiO2/Si(100)基底上制备Pb1-xLaxTiO3(PLT,x<0.2)薄膜,研究薄膜的结构及其介电、铁电性能.在600℃下退火1小时的PLT薄膜表现出单一的钙钛矿结构,(100)择优取向明显.在室温下PLT薄膜有典型的电滞回线.在x<0.2(摩尔比)的范围内,PLT薄膜相对介电常数则随着La的增加而增加.  相似文献   

5.
采用化学溶液沉积法,在Si[100]衬底上制备了掺La的(Bi0.8La0.2)2Ti2O7薄膜,研究了退火温度对薄膜结晶性及电学性能的影响.研究发现,随着退火温度的升高,样品的结晶性越来越好;漏电流密度随之降低,表明绝缘性逐渐增强.实验证明该薄膜具有良好的绝缘性和较高的介电常数.  相似文献   

6.
钛酸镧铅薄膜的介电、铁电性能研究   总被引:4,自引:1,他引:3  
甘肇强 《功能材料》2002,33(4):403-404
采用溶胶-凝胶法在Si衬底上制备了钛酸镧铅薄膜。通过对膜进行XRD、SEM、介电和铁电性能测试,研究了退火条件和掺镧量对薄膜性能的影响,结果发现在600℃下退火1h的PLT薄膜呈现钙钛矿结构;常温下,薄膜的矫顽场和剩余极化强度都随着掺镧量的增加而降低,其介电常数和介质损耗却随掺镧量的增加而增大。  相似文献   

7.
利用直流磁控溅射的方法制备掺La和未掺La的Ca_(1-x)La_xB_6(x=0,0.01,0.02,0.03)薄膜。利用原子力显微镜对薄膜的表面形貌及厚度进行表征。掺La的薄膜的厚度约为未掺杂的两倍;La的掺杂会使薄膜的晶粒尺寸变大。利用X射线光电子能谱对薄膜表面的化学组成进行检测。薄膜中Ca/La比接近理论值,没有检测到其它的铁磁性杂质及元素,尤其是Fe。Ca_(0.98)La_(0.02)B_6薄膜具有最大的室温饱和磁化强度,强度值为84.54 emu/cm~3。同时薄膜的饱和磁化强度值随薄膜厚度的增加而降低。在Ca_(1-x)La_xB_6薄膜中,B_6空位是薄膜磁性的主要来源,其它类型的缺陷例如晶界等,同样影响着薄膜磁性的大小。  相似文献   

8.
常温下采用射频磁控溅射技术在Pt/TI/SiO2/Si(100)基片上淀积(Pb0.9La0.1)TiO3薄膜,分别在550℃、570℃、600℃、630℃退火1h.采用X射线衍射、原子力显微镜和压电响应力显微镜检测不同退火温度的薄膜,讨论退火温度对薄膜结构、表面形貌和电畴结构的影响.结果表明:随着退火温度的升高,薄膜中钙钛矿相的含量增多,表面粗糙度和颗粒尺寸不断增大,薄膜从无畴状态变为以90°畴为主的多畴,而在退火升降温过程中,由于应力的影响,面外畴更多为取向向下的负畴.  相似文献   

9.
采用射频磁控溅射技术制备HfLaO薄膜, 利用X射线衍射(XRD)分析了薄膜的微结构, 通过紫外?可见光分光光度计测量了薄膜的透过谱, 计算了薄膜的折射率和禁带宽度, 利用原子力显微镜观察了薄膜的表面形貌. 结果表明: 沉积态HfLaO(La: 25%~37%)薄膜均为非晶态, 随着La掺入量的增加, HfLaO薄膜的结晶化温度逐渐升高, HfLaO(La~37%)薄膜经900℃高温退火后仍为非晶态, 具有优良的热稳定性, AFM形貌分析显示非晶薄膜表面非常平整. 随着 La掺入量的增加, HfLaO薄膜的透射率先降后增, 在可见光范围薄膜均保持较高的透射率(82%以上). HfLaO薄膜的折射率为1.77~1.87. 随着La掺入量的增加, HfLaO薄膜的折射率呈先增后降的变化趋势, 同时HfLaO薄膜的Eg逐渐降低, 分别为5.9eV(La~17%)、5.87eV(La~25%)、5.8eV(La~33%)和5.77eV(La ~37%).  相似文献   

10.
利用直流磁控溅射的方法制备掺La和未掺La的Ca1-xLaxB6 (x = 0, 0.01, 0.02, 0.03)薄膜。利用原子力显微镜对薄膜的表面形貌及厚度进行表征。掺La的薄膜的厚度约为未掺杂的两倍; La的掺杂会使薄膜的晶粒尺寸变大。利用X射线光电子能谱对薄膜表面的化学组成进行检测。薄膜中Ca/La比接近理论值, 没有检测到其它的铁磁性杂质及元素, 尤其是Fe。Ca0.98La0.02B6薄膜具有最大的室温饱和磁化强度, 强度值为84.54 emu/cm3。同时薄膜的饱和磁化强度值随薄膜厚度的增加而降低。在Ca1-xLaxB6薄膜中, B6空位是薄膜磁性的主要来源, 其它类型的缺陷例如晶界等, 同样影响着薄膜磁性的大小。  相似文献   

11.
A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.  相似文献   

12.
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……  相似文献   

13.
The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……  相似文献   

14.
Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.  相似文献   

15.
We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.  相似文献   

16.
Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.  相似文献   

17.
ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.  相似文献   

18.
Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.  相似文献   

19.
As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.  相似文献   

20.
TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.  相似文献   

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