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一种高性能聚碳酸酯薄膜的制备及表征 总被引:1,自引:0,他引:1
研究了一种高性能聚碳酸酯(PC)薄膜.将PC粉末配成不同浓度的聚碳酸酯溶液,用旋转涂覆法在玻璃衬底上制备了均匀透明的聚碳酸酯薄膜,并对材料和薄膜的热性能及光学性能等分别进行了表征.对材料通过示差扫描量热法(DSC)测得了玻璃化转变温度;对薄膜用紫外光谱法测量了吸收谱及光损耗,并用棱镜耦合仪测量了其折射率、膜厚及折射率随温度的变化;另外,还分析了不同实验条件对材料成膜性的影响.实验结果表明,这种新型聚碳酸酯材料具有高玻璃化温度和低吸收损耗等优点,适用于制作光波导器件芯层. 相似文献
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一种用于制备安德鲁反射样品的新方法 总被引:1,自引:0,他引:1
提供了一种用于安德鲁反射测量样品制备新方法.该方法采用聚焦粒子束刻蚀和磁控溅射,可以获得可控的、干净的、无应力的纳米接触用于自旋极化探测.所制备的样品中,磁性和非磁性材料样品的反射谱都表现出复杂的峰和谷结构,这些结构可能源于与界面相关的零偏压反常以及与激发态相关的准离子相互作用.对另一个Co40Fe40B20合金样品采用简单的钕针尖压针方法进行了对比性测量,反射谱中没有观察到谷结构,但谱结构出现较明显的热扩展,这种热扩展可能来源于界面处的非弹性输运.所有的反射谱目前还不能由现有的理论给出令人满意的解释.利用点接触反射方法获得可靠的自旋极化信息还有赖于接触界面特征的进一步分析.而一个更切合实际的、更完善的理论成为迫切的需要. 相似文献
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基于Si基沉积拉曼增强活性Au膜的制备与表征 总被引:2,自引:2,他引:0
研究了一种新的表面增强拉曼活性Au基底的制备方法,采用无电镀沉积方法,通过HF和HAuCl4的混合溶液对Si片进行处理获得具有不同形貌的Si基Au膜,利用扫描电子显微镜(SEM)分析了基底的表面形态和结构,测定结晶紫分子在基底表面的拉曼光谱。结果表明,Si基Au膜表面的表面增强拉曼散射(SERS)增强随制备时间的增加呈现先增强后减弱的趋势,增强效果优于常用的Au胶体系,是一种非常高效的拉曼活性增强基底。 相似文献
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分别采用射频磁控溅射、热壁化学气相沉积(CVD)、电泳沉积法制备GaN薄膜。利用扫描电镜(SEM)、荧光光谱仪对样品进行结构、形貌和发光特性的分析比较。射频磁控溅射方法中,把SiC中间层沉淀到Si衬底上,目的是为了缓冲由GaN外延层和Si衬底的晶格失配造成的应力。结果证实了SiC中间层提高了GaN薄膜的质量。热壁化学气相沉积法制备GaN晶体膜时,选择H2作反应气体兼载体,有利于GaN膜的形成。电泳沉积法显示所得样品为六方纤锌矿结构的GaN多晶薄膜。结果表明:溅射法制备的GaN薄膜结晶效果好;CVD法制备时GaN薄膜应用范围广;电泳沉积法操作方便、简单易行。 相似文献
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文章简要介绍了含磷酚醛树脂的合成、应用及性能,并利用其对环氧树脂的阻燃进行改性,在环保型FR-4层压板中进行应用,取得了较好的效果。 相似文献
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掺铕稀土配合物的光学树脂荧光光谱研究 总被引:2,自引:0,他引:2
报道了将多种稀土铕配合物复合于苯乙烯(ST)/甲基丙烯酸(HMA)的共聚体系,研究了含稀土配合物透明光学树脂的光学性能。发现其具有发光效率高,光谱呈现尖锐的线状谱带及相对于纯稀土配合物粉末来说掺有稀土配合物的光学树脂的发射产生光谱红移等特点。特别是用电子云重排效应(当中心稀土离子与不同配体结合时,其相同的J能级间的跃迁谱带位置略有移动的现象)解释了掺有稀土配合物的光学树脂发射光谱红移现象。并推断出在含稀土配合物复合于光学树脂后。稀土中心离子和配位原子间距离有所减小。 相似文献
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以N,N'-亚甲基双丙烯酰胺为交联剂,通过微波辐射制备了淀粉接枝丙烯酸高吸水树脂.研究了淀粉和引发剂类型、引发剂及交联剂用量、丙烯酸中和度、淀粉和单体的配比、微波辐射功率及辐射时间对吸水率的影响.结果表明,经过糊化后所制备的树脂吸水率明显提高,糊化过程减小了淀粉种类对吸水率的影响.过硫酸盐类引发剂是一类高效廉价的引发剂.当引发剂(过硫酸钾)和交联剂的用量分别为丙烯酸的0.3wt%和0.02wt%,中和度为60%,玉米淀粉和丙烯酸质量比为0.25时,经231W微波辐射4min,可获得吸水率为1110g·g~(-1)的高吸水树脂.利用微波技术制备吸水树脂可实现合成、干燥一步完成,且无须氮气保护,明显缩短反应时间、简化工艺、降低成本. 相似文献
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Kazuhiro Miyauchi Yukihiko Yamashita Naoya Suzuki Nozomu Takano 《Journal of Electronic Materials》2014,43(9):3411-3422
The self-assembly of solder powder on pads is attractive as a novel interconnection method between chips and substrates. However, the solder used in this method is limited to Sn-58Bi and Sn-52In. In contrast, Sn-3Ag-0.5Cu has been relatively less studied despite its wide use as a lead-free solder in assembling semiconductor packages. Hence, here, polymeric materials incorporating Sn-3Ag-0.5Cu solder powder were investigated for the self-assembly of the solder on pads at temperatures up to 260°C in a lead-free reflow process. The self-assembly of the solder was observed with an optical microscope through transparent glass chips placed on substrates covered with the polymeric materials incorporating the solder powder. Differential scanning calorimetry measurements were performed to confirm the behaviors of the reaction of the resins and the melting of the solder. When epoxy resin with a fluxing additive was used as a matrix, self-assembly of the solder was prevented by the cross-linking reaction. Conversely, when thermoplastic resin containing carboxyl groups was used as a matrix, the self-assembly of solder was successfully achieved in the absence of fluxing additives. The shear strength of interconnection using reflowfilm with lamination was sufficient and significantly increased during the reflow process. However, the shear strength of the reflowfilm showed cohesive failure, possibly because of the brittle intermetallic compounds (Ag3Sn, Au4Sn) network in bulk was lower than that of conventional solder paste that showed interfacial failure after the reflow process with a rapid cooling rate. 相似文献
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本文介绍了目前氰酸酯(CE)树脂的几种改性途径及其反应机理.包括热同性树脂、热塑性树脂、橡胶弹性体、晶须及含不饱和双键的化合物等改性方法.其中主要阐述了环氧(EP)树脂和双马来酰亚胺(BMI)树脂改性CE的机理及共聚体系的性能。 相似文献
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Na-doped p-type ZnO thin films have been realized by DC reactive magnetron sputtering with a set of metal-Zn targets doped with various Na contents and under different substrate temperatures, respectively. Hall effect measurement, field-emission SEM, X-ray diffraction and optical transmission were carried out to investigate the effects of Na content and substrate temperature on the properties of p-type films. Results indicate that all the Na-doped ZnO films are strongly (002) oriented, and have an average t... 相似文献
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Prakash N. K. Deenapanray C. S. Athukorala Daniel Macdonald W. E. Jellett E. Franklin V. E. Everett K. J. Weber A. W. Blakers 《Progress in Photovoltaics: Research and Applications》2006,14(7):603-614
This paper investigates the reactive ion etching of SiO2, Si3N4, and Si using CHF3/O2 plasma. In particular, we have characterized the time and rf power dependence of the carrier lifetimes in n‐ and p‐type FZ Si. The time dependence of reactive ion etching (RIE) at different rf powers provide insight into the two competing processes of damage accumulation and damage removal in the near‐surface region of the Si during plasma etching. The carrier lifetime, measured using the quasi‐steady‐state photoconductance (QSSPC) technique, has a quadratic dependence on the rf power, which can be related to changes in the dc self‐bias generated by the plasma at different rf powers. The change in carrier lifetime is similar in both n‐ and p‐type Si of the same doping concentration. Using this fact, together with the electronic properties of defects obtained by deep level transient spectroscopy (DLTS), we have modeled the injection‐dependence of the measured carrier lifetimes using the Shockley–Read–Hall model. The isochronal annealing behavior of plasma etched Si has also been studied. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献