Vacancy related defects in La0.5Sr0.5CoO3-δ thin films

Publication Type

Conference Paper

Authors

Abstract

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.

Journal

Materials Research Society Symposium - Proceedings

Volume

477

Year of Publication

1997

ISSN

02729172

Research Areas