A study was made, of vacancy-related defects in ferroelectric capacitors, by using a variable-energy positron beam. Heterostructures of (Pb0.9La0.1)(Zr0.2Ti0.8)O3, with La0.5Sr0.5CoO3 electrodes, were deposited by means of pulsed laser deposition and the effects of O deficiency were studied by using structures grown in O (760 or 10-5 Torr). The variable-energy positron beam depth profile revealed an increase in vacancy-related defects with increasing O non-stoichiometry. The formation of vacancy clusters in the La0.5Sr0.5CoO3 top electrode, and VPb-VO defects in the (Pb0.9La0.1)(Zr0.2Ti0.8)O3 layer, with increasing O deficiency, was deduced.

D.J.Keeble, B.Nielsen, A.Krishnan, K.G.Lynn, S.Madhukar, R.Ramesh, C.F.Young: Applied Physics Letters, 1998, 73[3], 318-20