Lead-free ceramics (Na_0.47Bi_0.47Ba_0.06)TiO₃, (Na_0.47Bi_0.47Ba_0.06)_0.95Ca_0.05TiO₃, and (Na_0.47Bi_0.47Ba_0.06)_0.95Sr_0.05TiO₃ (BNBT, BNBT-Ca, and BNBT-Sr, respectively) were obtained via solid-state sintering. Due to the different radii between Ca²⁺ and Sr²⁺, the mean radii of the A-site cations in BNBT-Ca, BNBT, and BNBT-Sr are different. Effects of radii of the A-site cations on crystallite structure, microstructure, piezoelectric, and dielectric properties of the ceramics were investigated comparatively. X-ray diffraction and Raman spectroscopy results reveal the lattice distortion due to the doping. With the increase in the mean radii of the A-site cations, lattice parameters, tolerance factor, band-gap energy, average size of grains, dielectric constant, and piezoelectric constant of the ceramics increase. The results imply that structure and electrical properties of BNBT-based ceramics are associated with radii of the A-site cations, which provides a possible route to tune structure and electrical properties of BNBT-based materials by changing radii of the A-site cations.

无铅陶瓷（Na _0.47 Bi _0.47 Ba _0.06）TiO ₃，（Na _0.47 Bi _0.47 Ba _0.06）_0.95 Ca _0.05 TiO ₃和（Na _0.47 Bi _0.47 Ba _0.06）_0.95 Sr _0.05 TiO ₃（BNBT，BNBT-Ca，分别通过固相烧结获得（BNBT-Sr和BNBT-Sr）。由于Ca ²⁺和Sr ²⁺之间的半径不同，BNBT-Ca，BNBT和BNBT-Sr中A位阳离子的平均半径是不同的。比较研究了A位阳离子半径对陶瓷的微晶结构，微结构，压电和介电性能的影响。X射线衍射和拉曼光谱结果显示出由于掺杂引起的晶格畸变。随着A位阳离子的平均半径的增加，晶格参数，容差因子，带隙能量，晶粒的平均尺寸，介电常数和陶瓷的压电常数增加。结果表明，BNBT基陶瓷的结构和电性能与A位阳离子的半径有关，这为通过改变A位阳离子的半径来调整BNBT基材料的结构和电性能提供了一条可能的途径。