Low Temperature Phase Transition in Sr(0.66)Ba(0.34)Nb2O6 single Crystal Fibers

Faria, J. L. B.; Paschoal, C. W. A.; Freire, P. T. C.; Ayala, A. P.; Melo, F. E. A.; Filho, J. Mendes; Santos, I. A.; Eiras, J. A.

Low Temperature Phase Transition in Sr(0.66)Ba(0.34)Nb2O6 single Crystal Fibers

Authors

Description

The structural changes in Sr(0.66)Ba(0.34)Nb2O6 single crystal fibers when the temperature decreases from 295 to 10 K is investigated by dielectric constant measurements and Raman spectroscopy. The anomaly observed in the plot of e is associated to the variation in the intensity and frequency of some Raman modes. We observe that the intensity of some low energy modes has a very singular behavior for the y(xz)y scattering geometry. In the high energy region (> 850 cm-1), a band at ~ 880 cm-1 disappears when the temperature is cooled down to 10K for the y(xz)y geometry and shifts to higher energy values for the y(zz)y geometry.