The origin of chemical inhomogeneity in lead-free potassium sodium niobate ceramic: Competitive chemical reaction during solid-state synthesis

Domain Engineering in Bulk Ferroelectric Ceramics via Mesoscopic Chemical Inhomogeneity

“…[19] Even though, the chemical inhomogeneity in synthesized products can be vanished to some extent via thermal homogenization at above 950 °C, as discussed in our previous work. [19] To demonstrate the effectiveness of the MCI effect, we purposely designed two series of samples by manipulating thermal homogenization. 2 series of KNN-xTa powders were calcined at 850 and 950 °C, to prepare chemically inhomogeneous and chemically homogeneous powders, respectively.…”

“…The competitive reaction can result in a strong chemical inhomogeneity in the synthesized products, depending on the choices of raw materials (e.g., powder size and crystal structure). [ 19 ] Even though, the chemical inhomogeneity in synthesized products can be vanished to some extent via thermal homogenization at above 950 °C, as discussed in our previous work. [ 19 ]…”

Simultaneous achievement of ultrahigh energy storage density and high efficiency in BiFeO3-based relaxor ferroelectric ceramics via a highly disordered multicomponent design

“…Moreover, the average grain size reduced remarkably to the submicron scale (<0.7 μm, Fig. 3(b)) after the introduction of KNN into the BLF–BST matrix, which is probably caused by the competition between various reactants during solid-state synthesis, 22 thus inhibiting grain growth in the BLF–BST–KNN ceramics. In ceramics with x > 0.05, the slightly increased average grain size could be ascribed to the increasing sintering temperature.…”

Comprehensive analysis of the temperature dependence of the crystal structure of (1−x)K0.5Na0.5NbO3–xBa(Li1/4Nb3/4)O3piezoelectric ceramics

“…The 0.99KNN–0.01BaLN ceramic is believed to adopt a cubic structure above T c due to a ferroelectric–paraelectric phase transition. Although the duration of forging at each temperature is considered to affect the phase equilibrium of KNN-based ceramics, the homogenization of KNN and 0.92KNN–0.02(Bi 0.5 Li 0.5 )TiO 3 –0.06BaZrO 3 ceramics with different Nb 2 O 5 reagents was investigated by Thong et al 41 by using in situ XRD on heating. Moreover, in situ crystal structure analysis by XRD for (1− x )(0.94Bi 1/2 Na 1/2 TiO 3 –0.06BaTiO 3 )– x KNN ceramics was performed to clarify the possibility for the application to a wide temperature range, though the duration of forging at each measurement temperature for in situ XRD analysis was not described in the literature.…”