不锈钢基板上合成碳纳米线圈及其场发射特性

摘要

Carbon nanocoils (CNCs) were synthesized by a thermal chemical vapor deposition (CVD) method over tin-coated type 202 stainless steel ( SS) plates ( Cr 15%, Mn 10%, Ni 1%) . It is considered that the calcination at 900℃ leads to the crazing of the SS surface, which causes the Fe ( Ni) and Sn to be fully mixed and forms active Fe ( Ni)-Sn-O catalyst particles suitable for the growth of CNCs. However, the Cr in the catalyst particles is below the limitation of detection, and its role is currently not un-derstood. The electron field-emission properties of as-grown CNCs dispersed on an n-type Si substrate were also investigated. It is found that the CNCs exhibit a low turn-on electric field of 1. 6 V/m. The distributions of electric fields on a stand-up and a laid-down CNC successfully explain the behavior of the Fowler-Nordheim ( F-N) plot. The field enhancement factor for the laid-down CNC is 2. 25 times larger than that for a laid-down multiwall carbon nanotube (CNT). This is because the helical morphology of the CNCs can reduce the screening effect produced by the surrounding substrate. In this case, CNCs can more easily emit electrons, and show promise for use in X-ray sources, field emission displays and other micro-or nano-devices.%在滴有锡溶液的普通不锈钢片上，利用热化学气相沉积法合成了碳纳米线圈。在900益煅烧导致不锈钢片表面的皲裂，使得Fe ( Ni)和Sn能够充分融合，并形成了适合于碳纳米线圈生长的具有活性的Fe( Ni)-Sn-O催化剂颗粒。研究分散在n型硅基板上的合成碳纳米线圈的场发射特性。结果表明碳纳米线圈具有大小为1.6 V/mm的低开启电场。单根直立的和躺倒的碳纳米线圈上的电场分布成功地解释了Fowler-Nordheim ( F-N)图的“行为”。同时发现躺倒的碳纳米线圈上的场增强因子茁是躺倒的碳纳米管上的2.25倍。这是因为碳纳米线圈的螺旋结构减少了周围基板对其的屏蔽效应。在这种情况下，碳纳米线圈更易发射电子，有望应用在X射线源，场发射显示器和其他微纳米装置中。