Dielectric and Electrical Properties of the Double Perovskite PbBaBiNbO6

The double perovskite PbBaBiNbO6 was synthesized by high-temperature solid-state reaction. Room-temperature x-ray data, energy-dispersive x-ray spectroscopy, and scanning electron microscopy of the sample confirmed formation of a single-phase compound and uniform distribution of grains of high density. Detailed studies of the dependence of the dielectric properties of the material on temperature and frequency confirmed its ferroelectric nature. The electrical transport properties of the material were indicative of non-exponential conductivity relaxation. We suggest this B-site Bi5+-doped ferroelectric perovskite material is a suitable candidate for the bulk photovoltaic effect and related solar applications. The low-lying 6s empty states of the electronegative Bi atom produce empty bands in the energy gap of the parent materials, effectively reducing the activation energy by similar to 1 eV, depending on the composition of the ferroelectric end member and the concentration of Bi5+ in the solid solution.