排序方式: 共有56条查询结果,搜索用时 31 毫秒
51.
CVD金刚石膜中1145cm~(-1)拉曼峰的研究 总被引:5,自引:1,他引:4
用拉曼光谱手段对CVD方法生长的金刚石膜,特别是其中最有争议的1145cm-1附近的拉曼峰进行了研究。用不同波长激光激发得到此峰的拉曼谱与量子尺寸选择效应所预期规律的相反,反驳了将1145cm-1附近的拉曼峰指认为纳米晶金刚石本征峰的说法。而通过对不同样品的比较,从侧面支持了将它归结为杂质,即反式聚乙炔的指认。更进一步通过分析不同尺寸的样品中杂质峰的相对强度,提出了这个峰的强度或许可以作为金刚石晶粒尺寸判据的建议。 相似文献
52.
53.
采用不同的方法裁剪高定向热解石墨(HOPG),制备纳米尺寸的石墨条.首先,发现用聚焦离子束(镓离子)刻蚀高定向热解石墨,可以得到边缘整齐程度在几十纳米的石墨条,另外,用 电子束曝光和反应离子刻蚀的工艺,可以得到最小尺寸为50 nm的纳米石墨图型 (nano-size d graphite pattern,纳米尺寸的多层石墨结构).采用了三种不同的方案制备反应等离子刻 蚀过程中需要的掩膜,分别是PECVD生长的SiO2掩膜,磁控溅射的方法生长的Si O2掩膜和PMMA光刻胶掩膜,并将三种方案的刻蚀结果做了对比.
关键词:
高定向热解石墨
聚焦离子束刻蚀
电子束曝光
反应离子刻蚀 相似文献
54.
55.
Electrospun fluorescein/polymer composite nanofibers and their photoluminescent properties
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Fluorescein/polyvinyl pyrrolidone (PVP) composite nanofibers with different fluorescein loadings (with a weight concentration of 0-5.0%) are fabricated via electrospinning. Morphologies, structures and photoluminescent (PL) properties of these straight, helical or wavelike fibers are characterized by scanning electron microscopy (SEM), fluorescence microscopy and a spectrophotometer. It is found that the maximum emission of the as-spun fluorescein/PVP fibers occurs at 510 nm. The PL intensity of the composite fiber increases with fluorescein concentration, then fluorescence quenching appears when the concentration reaches 1.67%. The mechanism of fluorescence quenching of fluorescein is discussed. In addition, the composite fibers exhibit a much stronger PL intensity than fluorescein/PVP bulk film owing to larger specific surface area, which makes them promising materials for biomedical applications such as probes and sensors. 相似文献
56.