Enhanced ferroelectric properties and lowered processing temperatures of strontium bismuth niobates with vanadium doping

Abstract

This letter reports on enhanced ferroelectric properties and lowered processing temperatures of a SrBi2(V, Nb)2O9 system with vanadium doping. The samples were prepared by reaction sintering of powder mixtures of constituent oxides. With partial substitution of niobium by vanadium cations (up to 10 at. %), the single-phase layered perovskite structure was preserved and the sintering temperature of the system was significantly lowered (∼ 200 °C). The incorporation of vanadium into the layered perovskite structure resulted in a shift of the Curie point to higher temperatures, from 435 to 457 °C with 10 at. % vanadium doping, and an increase in dielectric constant, from ∼700 to ∼1200 with 5 at. % vanadium doping, at their respective Curie points. Both enhanced Curie temperatures and dielectric constants at the Curie points indicate an increase in polarizability, which could be attributed to the increased “rattling space” due to the incorporation of much smaller vanadium cations. Further measurements also revealed that loss tangent of vanadium doped layered perovskites was the same as that without vanadium doping.