MECHANISM OF CHANGE IN THE EMISSION AND OPTICAL PROPERTIES OF W AND Mo AFTER BOMBARDMENT WITH LOW-ENERGY IONS.

The paper reports the results of study of composition, emission, and optical properties of polycrystalline W and Mo samples implanted with Ba+ ions and coated with submonolayer Ba atoms by applying Auger electron spectroscopy, secondary electron emission coefficient σ technique, as well as the photoelectron quantum yield Y. The experimental part was carried out by using the instrumentation and under vacuum Р ≈ 10-6 Pa. It is shown that during the implantation of Ba ions in the surface layers of refractory metals, a mechanical mixture of the W + Ba and Mo-Ba types is formed. It has been established that the values of the coefficient of secondary electron emission σ and the quantum yield of photoelectrons Y at the same value of the work function еφ in the case of implantation of Ba+ ions are much larger than in the case of deposition of atoms. The obtained experimental results are substantiated by theoretical calculations. [ABSTRACT FROM AUTHOR]