Ion-excited low-energy Auger electron emission from Ti and TiNi

Two distinct Auger transition features appear in the spectrum of electrons emitted from titanium surfaces by kiloelectronvolt argon ion bombardment. The main feature, corresponding to the electron-excited M₂₃VV transition and originating with Ti-Ti collisions inside the solid, is accompanied by a very narrow atomic-like line at a slightly lower energy attributed to electron emission from Ti atoms sputter ejected from the surface. Ion bombardment does not stimulate any spectral feature corresponding to the characteristic electron-excited Ti autoionization emission, 3p⁵3d²3d* to 3p⁶3d, which is severely attenuated upon simultaneous ion and electron excitations. The Ar⁺-excited emission from the Ti target is compared to that measured for the intermetallic compound TiNi.