Laser fluorescence studies of neutral particles sputtered from Cr, Cr 2O 3 and Cr 3C 2 targets

Abstract

We have performed laser induced fluorescence studies (LIF) of neutral Cr atoms sputtered from Cr, Cr 2O 3 and Cr 3C 2 targets under 15 keV Hr + bombardment. The yield and energy distributions of neutral Cr atoms sputtered from Cr 2O 3, and Cr 3C 2 targets are compared with the yields and energy distributions of Cr targets gradually covered with oxygen, nitrogen, ammonia and methane. The neutral Cr ground state yield is strongly influenced by the presence of oxygen on the surface but is independent of the pressure of nitrogen and methane. The yield of neutral Cr atoms from Cr 2O 3 targets is a factor of about 50, from Cr 3C 2 a factor 10 lower than the yield from clean metallic Cr targets. A factor of 100 was found for Cr atoms sputtered from oxidized Cr metal targets. Information about the contribution of excited atoms was obtained by bombardment induced light emission (BLE).