Temperature dependence of the Doppler-broadened spectra in Ag obtained by positron annihilation

Journal Article · Tue Apr 01 04:00:00 EST 1980 · Phys. Rev., B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.21.2655· OSTI ID:5489520

Jean, Y C; Lynn, K G; Dickman, J E

Doppler-broadened spectra have been measured in well-annealed high-purity polycrystalline silver as a function of temperature between 9 and 1098 K by a two-detector Doppler-broadening positron-annihilation technique. Those positrons which annihilate with high-momentum core electrons exhibit a larger fractional change in intensity than those which annihilate with the low-momentum electrons when positron trapping at vacancies occurs. The probability of annihilation with the high-momentum core electrons remains constant as a function of temperature before positron trapping at vacancies is detected. The vacancy-formation enthalpy obtained by applying the two-state trapping model to the high-momentum spectra is 1.11 +- 0.05 eV. The importance of utilizing high-momentum spectra for extracting vacancy-formation enthalpies is discussed, and a new structure is observed in the curves of the ratio between the high- and low-temperature momentum spectra.

• Research Organization: Brookhaven National Laboratory, Upton, New York 11973
• DOE Contract Number: EY-76-C-02-0016
• OSTI ID: 5489520
• Journal Information: Phys. Rev., B: Condens. Matter; (United States), Journal Name: Phys. Rev., B: Condens. Matter; (United States) Vol. 21:7; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ANNIHILATION
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
BASIC INTERACTIONS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DOPPLER BROADENING
ELECTROMAGNETIC INTERACTIONS
ELEMENTARY PARTICLES
ELEMENTS
ENTHALPY
FERMIONS
GAMMA SPECTRA
INTERACTIONS
LEPTONS
LINE BROADENING
METALS
PHYSICAL PROPERTIES
POINT DEFECTS
POSITRONS
SILVER
SPECTRA
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENTS
VACANCIES