氩对四针状氧化锌场发射性能的影响

Effect of Ar on the Field Emission Properties of Tetrapod Zinc Oxide

氧化锌是一种宽带半导体材料,由于其具有负电子亲和势,高的机械强度和良好的化学稳定性等特性,也被认为是一种很有发展潜力的场发射阴极材料。但是由于阴极材料在纳米量级,纳米材料的一些效应使其对工作的环境气体非常敏感。氩是采用薄膜型吸气剂的电真空器件中常见的残余气体成份。采用充气实验法研究了氩对氧化锌场发射的影响,得出其对氧化锌的场发射电流具有增强作用。由于氩的引入在一定程度上对系统起到了清洗的作用,系统内对氧化锌具有衰减作用的气体减少从而使得氧化锌发射电流在相同外加电压下增加。

A novel groove copper fibre composite wick copper board with good heat transfer performance was fabricated by plough-extrusion and sintering, but it is often compressed when applicating in heat transfer field, so the research on compression performance is very necessary. Compressive test was carried out to investigate the effects of porosity, copper fiber diameter and manufacturing parameters on the compressive properties of groove cop- per fiber composite wick copper board. During the compressive process, it was found that ： the larger fiber diame- ter, the smaller maximum stress. The maximum stress of copper fiber board with fine fiber diameter is 6. 9 MPa, and the maximum stress of medium fiber diameter is 6.2 MPa, the maximum stress of crude fiber diameter is 5.7 MPa. The higher sintering temperature, the larger corresponding stress, the longger sintering time, the larger corre- sponding stress value, the smaller porosity, the greater stress value. The reason of all experimental results is also analyzed.