Dielectrics

Synthesis, crystal structure, phase transitions and dielectric relaxation in La$^{3+}$-modified Sr$_{0.5}$Ba$_{0.5}$Nb$_2$O$_6$ ceramics

N. V. Makinyan^a, A. L. Bulanova^b, A. A. Zabolotnyi^b, A. V. Pavlenko<sup>a

a</sup> Southern Research Center of the Russian Academy of Sciences, Rostov-on-Don
^b Southern Federal University, Rostov-on-Don

Abstract: The crystal structure, dielectric and ferroelectric characteristics of Sr$_{0.5}$Ba$_{0.5}$Nb$_2$O$_6$ ceramics modified at the synthesis stage beyond the stoichiometry of 1 wt.% (weight percent) La$_2$O$_3$ (SBN50-La) have been studied. It is shown that ceramics are pure, La$^{3+}$ cations are embedded in A1 positions, and the parameters of the tetragonal unit cell are $a$ = 12.4800 $\mathring{\mathrm{A}}$, $c$ = 3.9354 $\mathring{\mathrm{A}}$. Analysis of the $\varepsilon'(T,f)$ and $\varepsilon''(T,f)$ dependencies revealed that SBN50-La is a relaxor ferroelectric. It is shown that the dielectric response of SBN50-La ceramics at $Т$ = 83–493 K and $f$ = 20–10$^6$ Hz has a contribution from three relaxation processes. The mechanisms of these processes are discussed.

Keywords: strontium barium niobate, dielectric characteristics, relaxor ferroelectric, dielectric relaxation.

Received: 10.07.2025
Revised: 18.07.2025
Accepted: 19.07.2025

DOI: 10.61011/FTT.2025.08.61316.183-25

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