Layer resolved spectroscopy of potassium adsorbed on a Ru(001) surface: Photoemission and thermal desorption study

Journal Article · Wed Nov 01 04:00:00 EST 1989 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.457531· OSTI ID:5370084

Hrbek, J ^[1]; Shek, M ^[2]; Sham, T K ^[3]; Xu, G ^[4]

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1. Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973 (US)
2. Department of Physics, Hunter College of CUNY, New York, New York 10021
3. Department of Chemistry, University of Western Ontario, London, Ontario N6A 5B7, Canada
4. Chemistry Department, Brookhaven National Laboratory, Upton, New York, 11973

High-resolution photoemission spectroscopy and thermal desorption were used to study the coverage dependence of the K 3{ital p}{sub 3/2,1/2} core levels of K overlayers on Ru(001). Three doublets were observed to evolve sequentially and to shift to higher binding energy with increasing coverage of potassium. The doublets were assigned to photoemission from the interface (first layer), bulk'' (second layer), and surface (third layer). Spin--orbit splitting was observed for the first time in the condensed potassium phase by photoemission. The results are discussed in terms of the equivalent core approximation using a Born--Haber cycle. In the thermal desorption data three coverage regimes can be distinguished: a first layer desorbing with first-order kinetics and a strongly decreasing heat of adsorption ({ital E}{sub {ital A}} =2.80--0.87 eV); a second layer with zero-order desorption kinetics and {ital E}{sub {ital A}} =0.78 eV; a third layer and multilayers with the same kinetic order but with {ital E}{sub {ital A}} increasing from 0.78 to 0.93 eV, which is close to the heat of sublimation of potassium.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5370084
• Journal Information: Journal of Chemical Physics; (USA), Journal Name: Journal of Chemical Physics; (USA) Vol. 91:9; ISSN JCPSA; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ACCELERATORS
ADSORPTION
ADSORPTION HEAT
ALKALI METALS
CYCLIC ACCELERATORS
DESORPTION
ELEMENTS
EMISSION
ENTHALPY
LAYERS
METALS
NSLS
PHOTOEMISSION
PHYSICAL PROPERTIES
PLATINUM METALS
POTASSIUM
RADIATION SOURCES
RUTHENIUM
SECONDARY EMISSION
SORPTION
SORPTIVE PROPERTIES
SUBLIMATION HEAT
SURFACE PROPERTIES
SYNCHROTRON RADIATION SOURCES
SYNCHROTRONS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENTS
TRANSITION HEAT