INVESTIGADORES
DAMONTE Laura Cristina
artículos
Título:
Positron annihilation in colourless centres in heavily gamma-irradiated NaCl
Autor/es:
F.J.NAVARRO; L. C. DAMONTE; J.L.ALVAREZ RIVAS; J.RIVAS; J.L.FERRERO
Revista:
JOURNAL OF PHYSICS CONDENSED MATTER
Editorial:
IOP
Referencias:
Año: 1995 vol. 7 p. 8273 - 8278
ISSN:
0953-8984
Resumen:
A detailed study of posivon lifetimes in heavily ga"a-inadiared NaU single
crystals, which undergo a pulsed thermal annealing treatment up to 740 T. is presented. Above
300 "C at which temperature the samples ae completely bleached, two exponential terms suffice
to fit lhe lifetime curve. While the shortest lifetime q does not depend upon the annealing
temperalure and has a value close to that found in unirradiated samples. the olher lifetime rzdetailed study of posivon lifetimes in heavily ga"a-inadiared NaU single
crystals, which undergo a pulsed thermal annealing treatment up to 740 T. is presented. Above
300 "C at which temperature the samples ae completely bleached, two exponential terms suffice
to fit lhe lifetime curve. While the shortest lifetime q does not depend upon the annealing
temperalure and has a value close to that found in unirradiated samples. the olher lifetime rzto 740 T. is presented. Above
300 "C at which temperature the samples ae completely bleached, two exponential terms suffice
to fit lhe lifetime curve. While the shortest lifetime q does not depend upon the annealing
temperalure and has a value close to that found in unirradiated samples. the olher lifetime rz"C at which temperature the samples ae completely bleached, two exponential terms suffice
to fit lhe lifetime curve. While the shortest lifetime q does not depend upon the annealing
temperalure and has a value close to that found in unirradiated samples. the olher lifetime rzfit lhe lifetime curve. While the shortest lifetime q does not depend upon the annealing
temperalure and has a value close to that found in unirradiated samples. the olher lifetime rzhas a value close to that found in unirradiated samples. the olher lifetime rz
exhibits a monotonic increase with annealing temperature and two recovery stages at about 340a monotonic increase with annealing temperature and two recovery stages at about 340
and 540 T, This pattern parallels the thermal recovery of the ionic conductivity of~irradialed
NaCI. It is suggested that n reflects the annihilation of positrons at cation vacancies thermally
released from radialion-induced divacancis. The 72 evolution with the annealing temperature
has been analysed in terms of a trapping model and a value of 1.96&0.08 eV for the divawncy
formation enthalpy is obtained.T, This pattern parallels the thermal recovery of the ionic conductivity of~irradialed
NaCI. It is suggested that n reflects the annihilation of positrons at cation vacancies thermally
released from radialion-induced divacancis. The 72 evolution with the annealing temperature
has been analysed in terms of a trapping model and a value of 1.96&0.08 eV for the divawncy
formation enthalpy is obtained.that n reflects the annihilation of positrons at cation vacancies thermally
released from radialion-induced divacancis. The 72 evolution with the annealing temperature
has been analysed in terms of a trapping model and a value of 1.96&0.08 eV for the divawncy
formation enthalpy is obtained.72 evolution with the annealing temperature
has been analysed in terms of a trapping model and a value of 1.96&0.08 eV for the divawncy
formation enthalpy is obtained.