Ferroelectric, dielectric and optic properties of Mn and Cr-doped Na_0.5Bi_0.5TiO₃ single crystals

The results from Raman, pyroelectric, dielectric and ferroelectric investigations of Mn and Cr-doped Na_0.5Bi_0.5TiO₃ (NBT) single crystals are presented. Influence of this substitution on the properties of NBT was observed. The influence manifests in several ways: (i) an increase of the electric conductivity, (ii) an increase of the remanent polarization and the decrease of coercive field, (iii) an improvement of pyroelectric properties and (iv) an increase of T_m temperature. Raman studies showed that substitution of a small amount of foreign ions affected local structure of the material. No evidence of the antiferroelectric phase was found in NBT-doped single crystals.