| Electric permittivity ε', conductivity and loss tangent of SBN61 strontium barium niobate single crystals obtained by the Stiepanov method: pure and doped with Cr (0,01 mol.%), Ni (0,01 mol.%), and Ce (0,0 1mol.%), both as a function of temperature (290-440K, at a frequency of 1 kHz and 10 kHz) and frequency (100 Hz-1 MHz) have been analyzed. The relaxor behavior of crystals has been described by a diffuseness constant value showing a deviation of the dielectric constant from the Curie-Weiss law. The results have been compared with the results for SBN33, SBN52:Cr and SBN58:Cr, Yb samples obtained by Czochralski growth, with different Sr/Ba ratios. Owing to the obtained results it may be concluded that the relaxor behavior of the investigated samples strongly depends on the crystal growth method and the kind of doping (lattice disorder), and the dependence on the Sr/Ba ratio is smaller. |
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