Miniature cold cathode ionization gauge based on composite films of carbon nanotubes and MgO nanoparticles

Composite films of carbon nanotubes (CNTs) and MgO nanoparticles are prepared by rubbing method, and their field emission (FE) properties are studied experimentally. It is found that, with an optimum proportion (~7 wt. %) of MgO nanoparticles mixed with CNTs, the FE properties of the composite films are dramatically improved, in lowering turn-on filed, suppressing the degradation of FE current, and increasing the FE uniformity and stability. Then, the CNTs-MgO composite films are used in miniature cold cathode ionization vacuum gauges, which exhibit good linearity in the pressure range of 2×10^-2 ~ 8×10^-6 Pa, with a gauge sensitivity of ~0.2 Pa^-1.