Novel insight into the structure and properties of lead-free dielectric Sr3TiNb4O15

Abstract

Sr₃TiNb₄O₁₅ has been synthesised and its structure and dielectric properties characterised. In contrast to previously reported results the compound has been found to form with Pna2₁ symmetry and unit cell dimensions a = 12.3631(19), b = 12.4027(19) and c = 7.7601(12) Å. Variable temperature studies show a phase transition from orthorhombic to tetragonal symmetry at approximately 625 K, much higher than previously reported. Temperature-dependent dielectric measurements have also been performed and these correlate very well with the observed phase transition temperature.