(K0.5Na0.5)(Nb1−xTax)O3 ceramics with a higher d33: Preparation from a two-stage microwave hydrothermal process

Synthesis routes for enhanced piezoelectric properties in spark plasma sintered Ta-doped KNN ceramics

“…Moreover, addition or/and substitution with Zr, Cu, Co, Mn, Li, Sr, Ta etc... have been investigated to enhance densification [10,[15][16][17][18][19][20][21][22][23]. Among them, tantalum substitution at 10 to 20% has been shown to effectively reduce grain growth and to gradually decrease the ortho-tetragonal transition and the Curie temperatures, leading to slightly increased piezoelectric properties [24][25][26][27][28].…”

“…However, for these Ta substitutions, difficulties were uncounted to densify ceramics and alternative processes were investigated (reactive template grain growth method, microwave hydrothermal technique) [24,27]. Jean et al have shown that, for 20 to 30 % Ta substitution on Nb-site combined with SPS technique, the piezoelectric properties have been sensitively improved compared to undoped KNN compositions.…”

Composite microstructures and piezoelectric properties in tantalum substituted lead-free K0.5Na0.5Nb1-xTaxO3 ceramics

“…Concerning bulk ceramics, Chen et al prepared Ta doped KNN ceramics from a powder obtained with a two-stage microwave hydrothermal process. They managed to reach a d33 value of 233 pC/N attributed to tantalum and to the morphology of their powders obtained with this process [30]. For their part, Hussain et al synthesized sodium excess and Tamodified (K0.470Na0.545)(Nb0.55Ta0.45)O3 textured ceramics by a reactive templated grain growth method.…”

“…The effects of tantalum as single doping element on niobium site was studied on thin films [25,26], single crystal [27][28][29] and bulk ceramics [30][31][32]. Concerning bulk ceramics, Chen et al prepared Ta doped KNN ceramics from a powder obtained with a two-stage microwave hydrothermal process.…”