Structure of NH/sub 3/ on Ni(111)

Conference · Tue Jan 01 04:00:00 EST 1980

OSTI ID:5002676

Madey, T E; Houston, J E; Seabury, C W; Rhodin, T N

In a recent study of the adsorption of NH/sub 3/ on NI(111) at T approx. 190 K using angle resolved UPS, it was concluded that NH/sub 3/ is molecularly adsorbed, and is bonded to the surface via the N atom with the H atoms oriented away from the surface. To study the bonding configuration using a direct and independent technique, we have examined NH/sub 3/ on Ni(111) using the electron stimulated desorption ion angular distribution (ESDIAD) method, coupled with temperature programmed desorption (TPD) and low energy electron diffraction (LEED). For NH/sub 3/ coverages achievable at T > 150K, (THETA approx. < 0.75 monolayers) the ESDIAD patterns are dominated by a halo of ion emission with little ion yield normal to the surface; the halo pattern is consistent with molecular NH/sub 3/ bonded to Ni via the N atom. Whereas angle-resolved UPS data indicate a specific azimutal registry of NH/sub 3/ with Ni(111) a well-defined azimuthal orientation is not evident from the ESDIAD results. Possible reasons for the differences between these results are examined, including final state effects in ESDIAD, and difference in sensitivity of the two methods to more than one possible configuration of the adsorbed NH/sub 3/.

• Research Organization: Cornell Univ., Ithaca, NY (USA)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5002676
• Report Number(s): SAND-80-2162C; CONF-801037-18
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102 -- Metals &amp; Alloys-- Structure &amp; Phase Studies
640301* -- Atomic
Molecular &amp; Chemical Physics-- Beams &amp; their Reactions
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMMONIA
ANGULAR DISTRIBUTION
COLLISIONS
CRYSTALS
DESORPTION
DISTRIBUTION
ELECTRON COLLISIONS
ELEMENTS
HYDRIDES
HYDROGEN COMPOUNDS
LOW TEMPERATURE
METALS
MONOCRYSTALS
NICKEL
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
SURFACES
TRANSITION ELEMENTS