He+ scattering on a TiO2(110) surface

Scattering of F atoms and anions on a TiO2(110) surface

“…Its overall intensity increases when annealed with oxygen and when the crystal becomes old (turns black and probably has many defects). The general characteristics of this azimuthal scan are similar to that for He scattering described previously [71].…”

“…In our previous paper [71] on He + scattering on TiO 2 we presented a discussion of some of the features in the azimuthal distributions based on classical binary collision code Marlowe, [72]. For He, also strong increases in the scattering intensity were observed for channelling along the main directions [0 0 1] and [0-1 1] and along secondary channels at the same angles as in Fig.…”

“…From He scattering measurements that we have performed [71], we would conclude that in general there is some deficiency in the bridging oxygen rows. Annealing with some oxygen seems to improve things but at the same time there would appear to be small ''clusters" of oxygen on the surface (see also [4]), which result in a larger ''background" in scattering (see the azimuthal scattering patterns below).…”

“…1. A discussion of these features related to scattering on the Ti/O plane and to the presence of the bridging oxygen atoms maybe found in [71]. In general terms, the variations of the F scattering yields with azimuth and energy show the expected behaviour: at the lowest energies, below 1 keV, i.e.…”

“…In the case of monocrystalline solids the situation is complicated by channeling effects. For surface scattering, the situation is intricate because regions far from the first atomic layer of the surface, where the electronic density decreases, may contribute to energy losses [58][59][60][61][62][63][64][65][66][67]. The trajectory lengths depend on the scattering conditions and very different trajectory types can be found.…”