BiFeO3(BFO) and (Ba-0.5, Sr-0.5) TiO3(BST)-buffered BFO capacitors were deposited on Pt/Ti/SiO2/Si(100) substrates. The effect of the thickness of the BST buffer layer, which varied from 5 to 15 nm, and the structures and electrical properties were investigated. The structures, morphologies, and leakage currents are enhanced by the insertion of a BST buffer layer. As BST film thickness increases, the remnant polarizations (Pr) decreases and the polarization-electrical field (P-E) hysteresis curve changes. Retention properties were obtained only on BST-buffered BFO. In terms of retention behaviors, we found a more stretched exponential law dominated region during retention times with increasing BST film thickness. Attractive retention values of BST-buffered BFO are also shown. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.024111jes] All rights reserved.