Absolute emission current density of O- from 12CaO•7Al2O3 crystal

Strong and high purity O- negative ion emission has been observed from a synthesized crystal 12CaO.7Al(2)O(3) surface. A muA/cm2-level O- emission from this material has been achieved at the surface temperature of 800 degreesC and the extraction field over 1000 V/cm, which is about three orders of magnitude higher than the current density emitted from the Y2O3-stabilized ZrO2 electrolyte surface. The strong emissivity of this material, as well as easy and economical fabrication, may provide a useful tool to generate the O- negative ion, which is expected to be one of the most important radicals for chemical syntheses and material modifications. (C) 2002 American Institute of Physics.