Effect of ZnO addition on the structure, microstructure and dielectric and piezoelectric properties of K0.5Na0.5NbO3 ceramics

Abstract

Microstructure, structure and electrical and dielectric properties of ZnO-doped K 0.5 Na 0.5 NbO 3 (KNN) ceramics were investigated. Powders were obtained by the conventional solid-state method. Samples doped with 0 to 1 mol% of ZnO were sintered at 1125 °C for 2 h. Through XRD spectra, the perovskite structure was detected, in addition to small peaks corresponding to secondary phases. It was also observed that zinc changed the microstructure and grain size of KNN ceramics. The addition of 0.5 mol% of Zn 2+ produced a softening effect in the ferroelectric properties of the material, and increased its final density. Conversely, the addition of 1 mol% of Zn 2+ reduced the sample densification.

Influence of Al2O3nanoparticle doping on depolarization temperature, and electrical and energy harvesting properties of lead-free 0.94(Bi0.5Na0.5)TiO3–0.06BaTiO3ceramics

“…19 Moreover, the increase in low-eld d 33 can be linked to an increase in the grain size as it is known that the larger gain gives the larger domain size with smaller domain wall width, thus enabling domain movement (under an applied electric eld). 20,56,57 The piezoelectric voltage coefficient (g 33 ) value is a key factor when evaluating piezoelectric energy harvester. It is a parameter that indicates the amount of electrical energy generated by the applied pressure.…”

Influence of surface modifiers on hydrothermal synthesis of K x Na(1−x)NbO3

“…5a and b, respectively, as a function of frequency and reaction conditions. These results are also summarized in Table 1, and it can be seen that samples obtained using additives presented dielectric constant values similar to those of K 0.5 Na 0.5 NbO 3 [20], whereas the sample obtained using Triton X-100 showed the highest dielectric constant. In general, losses and real permittivity decrease with frequency due to Debye effect, however this behaviour is more pronounced for the sample obtained using CTAB.…”

Single‐Crystal Ferroelectric‐Based (K,Na)NbO3 Microcuboid/CuO Nanodot Heterostructures with Enhanced Photo–Piezocatalytic Activity

“…Raman spectrum peaks related to bending F 2g (𝜈 5 ) (around 270 cm −1 ), stretching A 1g (𝜈 1 ) (600 cm −1 ), and stretching E g (𝜈 2 ) (530 cm −1 ) modes were detected; these modes are typical of KNN perovskite materials and are derived from the tiling of NbO 6 octahedra and cationic displacement. [44,45] To construct the KNN/CuO heterostructure, the CuO nanodots less than 5 nm were evenly decorated onto the surface of the KNN microcuboids (Figure 1e); this caused a color change from white (bare KNN) to light yellow (KNN/CuO), whereas the morphology and size distribution of KNN remained unaltered after the decoration of CuO nanodots (Figure S5, Supporting Information). The KNN-CuO heterointerface was captured by highresolution TEM (HR-TEM; Figure 1f).…”