Ion modification of the field-emission properties of diamond-graphite film structures

The patterns of variation of structure-phase, morphological, and field-emission parameters of nanocomposite diamond-graphite film structures, which were synthesized in microwave plasma of ethanol vapors, with the dose of irradiation with nitrogen ions with an energy of 20 keV are studied. It is found that the morphological parameters of diamond-graphite structures subjected to small-dose irradiation differ only slightly from those of nonirradiated samples. In contrast, the field-emission properties of irradiated samples are altered significantly. The maximum density of field-emission currents increases when the field-emission excitation thresholds are raised. The optimum doses of nitrogen ion implantation resulting in a more than fivefold increase (relative to nonirradiated structures) in the maximum density of field-emission currents are determined. The physical and chemical mechanisms involved in the modification of surface and near-surface properties of diamond-graphite structures subjected to various doses of ion irradiation are examined.