Slimi H, Oueslati A, Aydi A
Laboratory of Multifunctional Materials and Applications (LaMMA), LR16ES18, Faculty of Sciences of Sfax, University of Sfax BP 1171 3000 Sfax Tunisia
Laboratory of Spectroscopic Characterization and Optic Materials, University of Sfax, Faculty of Sciences of Sfax B.P. 1171 3000 Sfax Tunisia.
RSC Adv. 2021 Apr 19;11(24):14504-14512. doi: 10.1039/d1ra00952d. eCollection 2021 Apr 15.
(BaCa) (TiSn) Na Nb O (BCNTSNO) lead-free ceramics with compositions ( = 0.75, 0.8 and 0.85) were synthesized through the traditional solid-state reaction method. X-ray powder diffraction analysis showed the formation of a single phase compound crystallized in tetragonal space group 4. The evolution of Raman spectra displayed a disorder introduced into the structure, which favors a ferroelectric relaxor behavior. The dependence of the dielectric properties on temperature exhibited two composition ranges with different behaviors. Ferroelectric relaxor properties were observed for the compositions < 0.85 and the classical ferroelectric behavior for = 0.85. Lead free (BaCa) (TiSn) Na Nb O ceramics exhibited larger dielectric constants than those of parent crystal NaNbO, suggesting that it is a good candidate for lead-free ceramics in several industrial applications. Using UV-Vis spectroscopy, the optical band gap energy of ceramics (BaCa) (TiSn) Na Nb O is found at 2.89, 2.92, and 3.05 eV for = 0.75, 0.8 and 0.85, respectively.
采用传统固相反应法合成了组分为（= 0.75、0.8和0.85）的（BaCa）（TiSn）NaNbO（BCNTSNO）无铅陶瓷。X射线粉末衍射分析表明形成了一种在四方空间群4中结晶的单相化合物。拉曼光谱的演变显示结构中引入了无序，这有利于铁电弛豫行为。介电性能对温度的依赖性表现出两个具有不同行为的成分范围。对于<0.85的成分观察到铁电弛豫特性，而对于= 0.85则观察到经典铁电行为。无铅（BaCa）（TiSn）NaNbO陶瓷的介电常数比母体晶体NaNbO的介电常数大，这表明它在几种工业应用中是无铅陶瓷的良好候选材料。使用紫外可见光谱法，发现对于= 0.75、0.8和0.85，陶瓷（BaCa）（TiSn）NaNbO的光学带隙能量分别为2.89、2.92和3.05 eV。
