Influence of the crystal composition on the low temperature phase transition in barium sodium niobate

Abstract Barium sodium niobate crystals grown from melts with different starting compositions have been analysed using radiochemical method. Influence of the product composition on the low temperature phase transition (mm2 → 4mm on cooling) have been investigated through dielectric and birefringence measurements. The results suggest that this transition exists for crystals with Nb205 content ⩽ 50 mole %.