Determination of the low-work-function planes of LaB/sub 6/
A study of the temperature and orientation dependence of the field ion and electron emission and the average work function for a LaB/sub 6/ emitter have been carried out between 77 and 1800 K. These results indicate that the (310) surface is thermally stable and has the lowest work function of any single crystal plane of LaB/sub 6/. This result is confirmed by field-emission retarding-potential (FERP) work-function (phi) measurements at 300 K which gives phi (310) = 2.50eV. The results show the relative orientation dependence of the room-temperature work function (phi) measurements at 300 K which gives phi (310) < phi (210) < phi (100) < phi (110) < phi (111) < phi (211). This ordering is in accordance with the relative dipole contribution to the work function when surface reconstruction is included. The orientation dependence of the field electron emission is sensitive to field evaporation, thermal equilibration, and carbon contamination.
- Research Organization:
- Oregon Graduate Center, Beaverton (USA)
- OSTI ID:
- 6117066
- Report Number(s):
- AD-A-181269/2/XAB
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
BORIDES
BORON COMPOUNDS
CARBON
CHARGED PARTICLES
CONTAMINATION
ELECTRON EMISSION
ELEMENTS
EMISSION
EVAPORATION
FIELD EMISSION
FUNCTIONS
IONS
LANTHANUM BORIDES
LANTHANUM COMPOUNDS
MEASURING METHODS
NONMETALS
PHASE TRANSFORMATIONS
RARE EARTH COMPOUNDS
SENSITIVITY
WORK FUNCTIONS