PAES study of the positron thermal desorption from a Ge(100) surface
- Department of Physics, Brookhaven National Laboratory, Upton, New York (USA)
Positron induced Auger electron spectroscopy (PAES) from a clean Ge(100) surface was studied as a function of temperature. Three low-energy Auger peaks were detected at 50 eV, 90 eV and 100--150 eV, attributed to M{sub 2,3}M{sub 4}M{sub 4}, M{sub 2,3}M{sub 4}V and M{sub 1}M{sub 4}M{sub 4} Auger transitions, respectively. An estimated 4({plus minus}1)% of the surface trapped positrons annihilate with Ge 3p level electrons. The PAES yield from a Ge(100) surface is reduced at elevated temperatures, in accordance with an activation process found earlier in several Ps fraction experiments. A desorption model adopted from these studies does not accurately describe the PAES intensity at higher temperatures ({gt}500 {degree}C), which levels off at 5% of the room temperature value. Possible sources for the discrepancy are discussed. On a Ge(100) surface, an upper limit for the Ps emission near the melting point is 97%. The error in calibration parameters due to the earlier assumption of 100% Ps emission from Ge surfaces seems to induce only small errors to the Ps fraction measurements.
- OSTI ID:
- 5020570
- Report Number(s):
- CONF-900798-; CODEN: APCPC
- Journal Information:
- AIP Conference Proceedings (American Institute of Physics); (United States), Vol. 218:1; Conference: 4. international workshop on slow-positron beam techniques for solids and surfaces, London (Canada), 3-6 Jul 1990; ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
GERMANIUM
POSITRON COLLISIONS
POSITRONS
ANNIHILATION
DESORPTION
AUGER ELECTRON SPECTROSCOPY
POSITRONIUM
SURFACE PROPERTIES
TEMPERATURE DEPENDENCE
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
BASIC INTERACTIONS
COLLISIONS
ELECTROMAGNETIC INTERACTIONS
ELECTRON SPECTROSCOPY
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
INTERACTIONS
LEPTONS
MATTER
METALS
PARTICLE INTERACTIONS
SPECTROSCOPY
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656002 - Condensed Matter Physics- General Techniques in Condensed Matter- (1987-)
360104 - Metals & Alloys- Physical Properties