Direct inelastic scattering of N/sub 2/ from Ag(111). III. Normal incident N/sub 2/

Journal Article · Thu Dec 01 04:00:00 EST 1988 · J. Chem. Phys.; (United States)

OSTI ID:6719536

Kummel, A C; Sitz, G O; Zare, R N; Tully, J C

We have probed the angular momentum orientation of N/sub 2/ scattered from cold Ag(111) when the N/sub 2/ approaches the surface along the surface normal. Using resonance enhanced multiphoton ionization (REMPI) and pulsed molecular beam techniques, we are able to probe the flux backscattered along the surface normal. In accordance with the restrictions on cylindrically symmetric systems, the molecules backscattered along the surface normal have no angular momentum orientation nor does the entire scattered flux integrated over all exit angles. However, for detection away from the surface normal, we observe substantial angular momentum orientation; the degree and direction of orientation depends upon the rotational state being probed. Molecular dynamics calculations reproduce the experimental results semiquantitatively. The calculations show that for N/sub 2/ incident along the surface normal, the exit angle is largely determined by the two-dimensional impact parameter of the molecule within the crystal unit mesh. However, the final rotational state, orientation, and alignment are determined largely by the molecular orientation geometry of the N/sub 2/ during the collision. In essence, we have found a dynamical process which can partially differentiate between the two hidden initial conditions in a gas--surface collision: the two-dimensaional impact parameter and the molecular orientation geometry.

• Research Organization: Department of Chemistry, Stanford University, Stanford, California 94305
• OSTI ID: 6719536
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 89:11; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

656003* -- Condensed Matter Physics-- Interactions between Beams & Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALIGNMENT
ANGULAR MOMENTUM
BEAMS
COLLISIONS
ELEMENTS
ENERGY LEVELS
ENERGY TRANSFER
EXCITED STATES
INCIDENCE ANGLE
INELASTIC SCATTERING
METALS
MOLECULAR BEAMS
MOLECULE COLLISIONS
MULTI-PHOTON PROCESSES
NITROGEN
NONMETALS
ORIENTATION
ROTATIONAL STATES
SCATTERING
SILVER
SURFACES
TRANSITION ELEMENTS