New highly polar semiconductor ferroelectrics through d 8 cation-0 vacancy substitution into PbTi0 3: A theoretical study

Abstract

We use first-principles density functional theory (DFT) calculations to investigate the ground-state structures of PbTi0 3 solid solutions containing Ni, Pd, and Pt. Anomalous effective charges are reported, including the first report of negative Born effective charges for nominal +2 cations. We predict that these proposed materials will display a decreased band gap when compared to PbTi03 while maintaining or enhancing polarization. They are promising candidates for use as semiconducting ferroelectric substrates for solar conversion devices.© 2008 American Chemical Society.