Dielectric Relaxation Phenomena in SBN Single Crystals Doped with Ce

Abstract

The dielectric study of Sr 0.73 Ba 0.27 Nb 2 O 6 :Ce (SBN) crystals along [010] crystallographic axis was performed in the temperature region of 310-360 K and frequency range from 25 Hz up to 1 MHz. The thermal dipole relaxation of quasi-Debye-type for this orientation of sample was observed in both investigated structural phases. The phase transition was most clearly seen from the temperature dependence of the relaxation time at T c = 320 K. The relaxation processes were related to the collective oscillations of the Nb-O bonds in the two different type corner-sharing NbO 6 octahedra aligned along c-axis.

Thermoelectric Properties of Reduced Polycrystalline Sr0.5Ba0.5Nb2O6 Fabricated Via Solution Combustion Synthesis

“…These NbO 6 octahedra are arranged in such a manner that three different interstitial sites exist in the unit cell. Only Sr atoms occupy the 12‐fold coordinated tetragonal A1 sites, whereas both Sr and Ba atoms occupy the larger 15‐fold coordinated pentagonal A2 sites; trigonal C sites are vacant, as are one‐sixth of the total A1 and A2 sites . Such a complex structure allows for the effective scattering of phonons and thus, thermal conductivities as low as 0.8 W/m·K have been reported for SBN single crystals .…”

“…Only Sr atoms occupy the 12-fold coordinated tetragonal A1 sites, whereas both Sr and Ba atoms occupy the larger 15-fold coordinated pentagonal A2 sites; trigonal C sites are vacant, as are one-sixth of the total A1 and A2 sites. 20,21 Such a complex structure allows for the effective scattering of phonons and thus, thermal conductivities as low as 0.8 W/mÁK have been reported for SBN single crystals. 22 In addition, a change in the SBN stoichiometry leads to variations in the ferroelectric-paraelectric phase transition temperature.…”