Hyperthermal alkali-ion scattering from a metal surface: A theoretical study of the potential

Journal Article · Wed Oct 15 04:00:00 EDT 1986 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.34.5030· OSTI ID:5240682

van den Hoek, P J; Tenner, A D; Kleyn, A W; Baerends, E J

The K/sup +/-W ion-atom scattering potential is calculated with the Hartree-Fock-Slater linear combination of atomic orbitals (HFS-LCAO) method. For hyperthermal (10--100 eV) K/sup +/ scattering from a W(110) surface, classical-trajectory calculations are performed, where the K/sup +/-W(110) ion-surface potential is represented by a sum of pairwise-calculated (HFS-LCAO) K/sup +/-W potentials. The results of these classical-trajectory calculations are compared with experiment and with the results of similar trajectory calculations using a sum of Ziegler-Biersack-Littmarck ''universal'' pair potentials. From these comparisons, it turns out that the HFS-LCAO pair potential is able to reproduce well on-top-site hyperthermal K/sup +/ scattering from a W(110) surface, contrary to the Ziegler-Biersack-Littmarck potential, which clearly does not work very well in this low-energy range. The inability of the HFS-LCAO pair potential to give a proper description of K/sup +/ scattering from the hollow site of the W(110) surface unit cell can be ascribed to the breakdown of a summation of pair potentials. This is clear from the difference between the sum of the calculated K/sup +/-W ion-atom potentials and a calculated K/sup +/-W/sub 5/ ion-cluster potential, the cluster representing the W(110) surface. The ion-cluster calculations indicate an extra repulsion of about 10% at the center of the W(110) surface unit cell. This extra hollow-site repulsion can be explained by analyzing the properties of the exchange (Pauli, Born) repulsions between the K/sup +/ ion and (i) one W atom and (ii) the W(110) surface (W/sub 5/ cluster) at the hollow site.

• Research Organization: FOM Institute for Atomic and Molecular Physics, Kruislaan 407, NL-1098X Amsterdam, The Netherlands
• OSTI ID: 5240682
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 34:8; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

640301* -- Atomic
Molecular & Chemical Physics-- Beams & their Reactions
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANGULAR DISTRIBUTION
CHARGED PARTICLES
CHEMICAL ANALYSIS
COLLISIONS
CRYSTAL FACES
DISTRIBUTION
ELEMENTS
ENERGY RANGE
EV RANGE
EV RANGE 10-100
HARTREE-FOCK METHOD
ION COLLISIONS
ION SCATTERING ANALYSIS
IONS
LCAO METHOD
METALS
NONDESTRUCTIVE ANALYSIS
POTASSIUM IONS
POTENTIALS
SIMULATION
SURFACE POTENTIAL
TRAJECTORIES
TRANSITION ELEMENTS
TUNGSTEN