KINETICS OF STRONTIUM OXIDE ON TUNGSTEN

Journal Article · Fri Jan 01 04:00:00 EST 1960 · Journal of Chemical Physics (U.S.)

DOI:https://doi.org/10.1063/1.1700902· OSTI ID:4176427

Cape, J A; Coomes, E A

Field electron microscopy was used to study the kinetics of strontium oxide on tungsten in the range 900 to 2200 deg K. Reactions take place on the {111} and {100} which have high concentrations of four nearest neighbor surface atoms. Below 1150 deg K there is some evidence for the dissociation of SrO and migration of Sr to the {110} edges where clusters of crystallites are formed. Two modifications of field emission patterns associated with the (Sr-O--W) complex within 1150 to 1550 deg K are tentutively identified with the basic and nornaal tungstate; apparently the first goes over to the second with an activation energy of approximately 60 kcal as determined from desorption data. An unusually sharp decrease in Fowler-Nordheim work function occurs during this reaction. In the later stages of desorption above 1550 deg K patterns identifiable with an oxygen-tungsten surface are obtained. Desorption at this stage takes place with an activation energy of approximately 140 kcal. (auth)

• Research Organization: Univ. of Notre Dame, Ind.
• Sponsoring Organization: USDOE
• NSA Number: NSA-14-007352
• OSTI ID: 4176427
• Journal Information: Journal of Chemical Physics (U.S.), Journal Name: Journal of Chemical Physics (U.S.) Vol. Vol: 32; ISSN JCPSA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ADSORPTION
ATOMS
CHEMISTRY
DESORPTION
ELECTRON MICROSCOPY
EMISSION
FOWLER- NORDHEIM THEORY
FOWLER-NORDHEIM WORK FUNCTION
REACTION KINETICS
STRONTIUM OXIDES
SURFACES
TEMPERATURE
TUNGSTATES
TUNGSTEN