Effects of Nd substitution on the polarization properties and electronic structures of bismuth titanate single crystals

Abstract Single crystals of Nd-substituted Bi 4 Ti 3 O 12 ferroelectrics were grown by a self-flux method, and the effects of Nd substitution on the polarization properties and optical transmission spectra of the crystals have been investigated. Bi 3.52 Nd 0.48 Ti 3 O 12 crystals showed a smaller remanent polarization along the a axis of 29 μC/cm 2 than Bi 4 Ti 3 O 12 crystals (46 μC/cm 2 ), and this result is in good qualitative agreement with the calculation of the spontaneous polarization based on Rietveld analysis of neutron diffraction. Electronic band structure calculations using the structural data suggest that the orbital hybridization between the Nd 5d and O 2p states stabilizes oxide ions in the perovskite layers, which is consistent with the much smaller leakage current observed for Nd-substituted crystals.