Abstract In this work, Ba0.9Sr0.1TiO3, Ba0.7Sr0.3TiO3, Ba0.5Sr0.5TiO3, Ba0.5Ca0.25Sr0.25TiO3 and Ba0.5Ca0.5TiO3 have been synthesized to evaluate the influence of mono and co-substitution of A-site dopants (Sr2+ and Ca2+) on the structural, electrical and optical properties of BaTiO3 ceramics. Sr2+ added samples showed a tetragonal structure which became slightly distorted with increasing Sr2+ concentration and finally achieved a cubic structure for x = 0.50. Ba0.5Ca0.5TiO3 also retained their tetragonality with limited solubility. Presence of second phase, CaTiO3 demonstrated the fact of restricted solubility. The concurrent effect of Sr2+ and Ca2+ didn't alter the tetragonal structure. Sr2+ substitution enhanced the apparent density as well as grain size which stimulated the domain wall motion and improved dielectric properties. However, the ferroelectric nature of Ba1-xSrxTiO3 was poor due to the redistribution of point defect at grain boundary. The optical band gap was found to be reduced from 3.48 eV to 3.28 eV with increasing Sr2+ content. Co-substitution of cations improved the electrical property significantly. The highest value of dielectric constant was found to be ∼547 for Ba0.5Ca0.25Sr0.25TiO3 ceramics. Both Ba0.5Ca0.25Sr0.25TiO3 and Ba0.5Ca0.5TiO3 had developed P-E loop having lower coercive field and moderate optical band gap energy. Co-doping with Sr2+ and Ca2+ was a good approach enhancing materials electrical as well as optical property.

中文翻译：

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Sr2+和Ca2+的单取代和共取代对钛酸钡陶瓷结构、电学和光学性能的影响

摘要 本工作合成了 Ba0.9Sr0.1TiO3、Ba0.7Sr0.3TiO3、Ba0.5Sr0.5TiO3、Ba0.5Ca0.25Sr0.25TiO3 和 Ba0.5Ca0.5TiO3，以评估单取代和共取代的影响。 A 位掺杂剂（Sr2+ 和 Ca2+）对 BaTiO3 陶瓷结构、电学和光学性能的影响。添加 Sr2+ 的样品显示出四方结构，随着 Sr2+ 浓度的增加，该结构略微扭曲，最终在 x = 0.50 时实现立方结构。Ba0.5Ca0.5TiO3 也保留了它们的四方性，但溶解度有限。第二相CaTiO3 的存在证明了溶解度受限的事实。Sr2+ 和Ca2+ 的同时作用没有改变四方结构。Sr2+ 取代增强了表观密度和晶粒尺寸，从而刺激了畴壁运动并改善了介电性能。然而，由于晶界处点缺陷的重新分布，Ba1-xSrxTiO3 的铁电性质很差。发现随着 Sr2+ 含量的增加，光学带隙从 3.48 eV 减小到 3.28 eV。阳离子的共取代显着改善了电性能。发现 Ba0.5Ca0.25Sr0.25TiO3 陶瓷的介电常数的最高值为 ~547。Ba0.5Ca0.25Sr0.25TiO3 和 Ba0.5Ca0.5TiO3 都开发了具有较低矫顽力和中等光学带隙能量的 PE 环。与 Sr2+ 和 Ca2+ 共掺杂是增强材料电学和光学性能的好方法。阳离子的共取代显着改善了电性能。发现 Ba0.5Ca0.25Sr0.25TiO3 陶瓷的介电常数的最高值为 ~547。Ba0.5Ca0.25Sr0.25TiO3 和 Ba0.5Ca0.5TiO3 都开发了具有较低矫顽力和中等光学带隙能量的 PE 环。与 Sr2+ 和 Ca2+ 共掺杂是增强材料电学和光学性能的好方法。阳离子的共取代显着改善了电性能。发现 Ba0.5Ca0.25Sr0.25TiO3 陶瓷的介电常数的最高值为 ~547。Ba0.5Ca0.25Sr0.25TiO3 和 Ba0.5Ca0.5TiO3 都开发了具有较低矫顽力和中等光学带隙能量的 PE 环。与 Sr2+ 和 Ca2+ 共掺杂是增强材料电学和光学性能的好方法。