Synthesis, structure, spectroscopic and transport properties of (Ba_1-ISr_x)NbO₃

Oxides of the (Ba_1-xSr_x)NbO₃ system (x = 0, 0.1, 0.4, 0.5, 0.7, and 1.0) have been synthesized by a solid-state reaction technique with zirconium metal. The oxides with x = 0, 0.1, 0.5, 0.7, and 1.0 present a simple cubic perovskite structure while a distorted perovskite is observed in the oxide with x = 0.4. Infrared spectra showed the presence of two absorption maxima in the case of the cubic perovskites and only one for the distorted perovskite. The observed vibration modes have been associated with stretching vibration modes of a [NbO₆] octahedral entity. The substitution of barium by strontium influences the transport properties specially in the case of the (Ba_0.6Sr_0.4)NbO₃ oxide.