TY - CPAPER
KW - Cooling
KW - Thin films
KW - Laser ablation
KW - Lanthanum compounds
KW - Crystal defects
KW - Metallic films
KW - Doppler effect
KW - Positron annihilation
AU - D.J Keeble
AU - S Madhukar
AU - B Nielsen
AU - A Krishnan
AU - P Asoka-Kumar
AU - S Aggarwal
AU - Ramamoorthy Ramesh
AU - E.H Poindexter
AB - Laser ablated La0.5Sr0.5CoO3-δ thin films have been studied by Doppler-broadening-detected positron annihilation using a variable-energy positron beam. The oxygen partial pressure during cooling from the growth temperature was altered through the range 760 torr to 10-5 torr to change the oxygen non-stoichiometry of the films. The measured Doppler broadened lineshape parameter S was found to increase with increasing oxygen nonstoichiometry. For films cooled with an oxygen partial pressure of ≤10-4 Torr positron trapping to monovacancy type defects is inferred. It is proposed that Se ion oxygen vacancy complexes are likely trapping sites. For the film cooled in 10-5 torr oxygen the magnitude of the increase in S, with respect to that measured from the film cooled in 760 Torr oxygen, showed positron trapping to vacancy cluster defects is occurring.
BT - Proceedings of the Materials Research Society Symposium -
LA - eng
N1 - cited By 2
N2 - Laser ablated La0.5Sr0.5CoO3-δ thin films have been studied by Doppler-broadening-detected positron annihilation using a variable-energy positron beam. The oxygen partial pressure during cooling from the growth temperature was altered through the range 760 torr to 10-5 torr to change the oxygen non-stoichiometry of the films. The measured Doppler broadened lineshape parameter S was found to increase with increasing oxygen nonstoichiometry. For films cooled with an oxygen partial pressure of ≤10-4 Torr positron trapping to monovacancy type defects is inferred. It is proposed that Se ion oxygen vacancy complexes are likely trapping sites. For the film cooled in 10-5 torr oxygen the magnitude of the increase in S, with respect to that measured from the film cooled in 760 Torr oxygen, showed positron trapping to vacancy cluster defects is occurring.
PB - MRS, Warrendale, PA, United States
PY - 1997
SP - 229
EP - 233
T2 - Proceedings of the Materials Research Society Symposium -
T3 - Materials Research Society Symposium -
TI - Vacancy related defects in La0.5Sr0.5CoO3-δ thin films
VL - 477
SN - 02729172
ER -