Chemical composition and tolerance factor at the morphotropic phase boundary in (Bi0.5Na0.5)TiO3-based piezoelectric ceramics

Crystal Structure, dielectric and ferroelectric properties of (Bi0.5Na0.5)TiO3–(Ba,Sr)TiO3 lead-free piezoelectric ceramics

“…According to the previous work, the Ba 2+ /Sr 2+ ions (R Ba 2+ /R Sr 2+ = 1.61/1.44 Å ) with larger ionic radii enable to diffuse into BNT lattice to replace the positions of Bi 3+ and Na + (R Bi 3+ /R Na + = 1.40/1.39 Å ) and eventually induce a phase transition from rhombohedral to tetragonal phase when sufficient amount of Ba 2+ /Sr 2+ ions are incorporated [18]. Here we take the (Ba 0.7 Sr 0.3 )TiO 3 (BST30) compound as non-BNT member and dopes it into BNT in various ratios in order to inspect the effect of Ba 2+ /Sr 2+ ratio on the resulting structural characteristics of the formed solid solution.…”

“…For example, highly textured BNT-BaTiO 3 ceramic can be fabricated by reactive templated grain growth (RTGG) method and shows a significant improvement in piezoelectric properties [16]. The relation between MPB composition and tolerance factor in these BNT-based ceramics had been revealed in our previous study [18]. However, a decrease of depolarization temperature (T d ) is always found during the attempts of modifying piezoelectric properties by doping other materials, and thus limits its application.…”

“…Ferroelectric (Ba 1−a Sr a )TiO 3 (BST) material is widely used in microelectronic device due to its high dielectric properties and is a good doping compound to improve the dielectric properties of pure BNT [25]. According to the tolerance factor calculation as mentioned above [18], the MPB composition of (1 − x)(Bi 0.5 Na 0.5 )TiO 3 -x(Ba 1−a Sr a )TiO 3 system is corresponding to a tolerance factor of around 0.991 in which the x value shifts from 0.06 to 0.08 as the Sr 2+ content increases from a = 0-0.3. In this work, the solid solution of (1 − x)(Bi 0.5 Na 0.5 )TiO 3 -x(Ba 1−a Sr a )TiO 3 (x = 0-0.12, a = 0-0.3) was prepared.…”

Effect of KNbO3 on physical and electrical properties of lead-free BaTiO3 ceramic

“…In general, the perovskite structure is stable in the region 0.880 < t < 1.090, and the symmetry is higher as the t value is close to 1 [22]. The t value also provides an indication about how far the atoms can move from the ideal packing positions and be still tolerated in the perovskite structure.…”

Structure and dielectric properties of (Na0.5Bi0.5)TiO3–SrTiO3 thick films derived from polyvinylpyrrolidone-modified chemical solution

“…It was reported that the dielectric, ferroelectric, and piezoelectric properties of NBT can be optimized by the introduction of SrTiO 3 (abbreviated as ST), which possesses a perovskite-structured paraelectric phase with a cubic symmetry at room temperature [15]. However, these studies are almost limited to the bulk ceramics, and only few attempts at the fabrication of lead-free thick film have been made by using chemical solution route [16][17][18][19]. The dielectric tunability of NBT-xST thick films has rarely been reported yet.…”