Low-temperature positron lifetime and Doppler-broadening measurements for single-crystal nickel oxide containing cation vacancies

Conference · Tue Jan 01 00:00:00 EST 1985

OSTI ID:5912666

Waber, J T; Snead, Jr, C L; Lynn, K G

Lifetime and Doppler-broadening measurements for positron annihilation in substoichiometric nickelous oxide have been made concomitantly from liquid-helium to room temperature. The concentration of cation vacancies is readily controlled by altering the ambient oxygen pressure while annealing the crystals at 1673/sup 0/K. It was found that neither of the three lifetimes observed or their relative intensities varied significantly with the oxygen pressure, and the bulk rate only increased slightly when the specimen was cooled from room to liquid-helium temperatures. These results are interpreted as indicating that some of the positrons are trapped by the existing cation vacancies and a smaller fraction by vacancy clusters.

• Research Organization: Northwestern Univ., Evanston, IL (USA); Brookhaven National Lab., Upton, NY (USA)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5912666
• Report Number(s): BNL-36289; CONF-850169-8; ON: DE85010238
• Resource Relation: Conference: 7. international conference on positron annihilation, New Delhi, India, 6 Jan 1985
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
NICKEL OXIDES
VACANCIES
CATIONS
DOPPLER BROADENING
POSITRONS
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
CHALCOGENIDES
CHARGED PARTICLES
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
ELEMENTARY PARTICLES
FERMIONS
IONS
LEPTONS
LINE BROADENING
NICKEL COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
POINT DEFECTS
TRANSITION ELEMENT COMPOUNDS
360202* - Ceramics
Cermets
& Refractories- Structure & Phase Studies