Raman measurements of the ferroelectric Ba_0.4Sr_0.6Nb₂O₆

Abstract

Abstract Using Raman spectroscopy, we have measured the A1(TO) and E(TO) phonons in the tungsten bronze structured ferroelectric Ba0.4Sr0.6Nb2O6 (BSN). We observe phonon anomalies associated with Tc and also with a temperature≈ 425°C. The latter is in the region where index of refraction measurements indicate the onset of a local polarization. By quenching the crystal from high temperatures, Tc can be shifted. We find that the phonon anomalies shift corresponding to the new Tc values.