Defects in an ultrathin Au/La2/3Sr1/3MnO 3/SrTiO3 (Au/LSMO/STO) heterostructure displaying electroresistive behavior were studied using variable energy positron annihilation spectroscopy. Vacancy-like defects were found to be the dominant positron traps in the LSMO and STO thin perovskite oxides with a number density > 1017 cm-3 and 2 × 1017 cm -3 in the STO substrate. High defect density was revealed by strong positron trapping at the Au/LSMO interface. Oxygen deficiency in LSMO would be the main source of these traps. Besides, a low density of sub-nano voids of ∼6Å was found in the substrate and in the thin LSMO/STO films. © 2011 American Institute of Physics.    «

Defects in an ultrathin Au/La2/3Sr1/3MnO 3/SrTiO3 (Au/LSMO/STO) heterostructure displaying electroresistive behavior were studied using variable energy positron annihilation spectroscopy. Vacancy-like defects were found to be the dominant positron traps in the LSMO and STO thin perovskite oxides with a number density > 1017 cm-3 and 2 × 1017 cm -3 in the STO substrate. High defect density was revealed by strong positron trapping at the Au/LSMO interface. Oxygen deficiency in LSMO would be the ma...    »