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BaZr0.1Ti0.89Fe0.01O3 ceramics sintered at 1240–1340 °C were prepared by solid-state method. The sample underwent phase transition from rhombohedral to orthorhombic phase, which changed the internal stress. Increasing the sintering temperature promoted grain growth (from 0.44 to 1.87 μm). The dielectric constant (ε = 4300) and diffusion coefficient (γ = 1.927) of the sample were improved significantly. The improvement mechanism of dielectric constant and dispersion phase transition was explained by the internal stress model and 90° domain structure in detail. [ABSTRACT FROM AUTHOR]

BaZr0.1Ti0.89Fe0.01O3(BZTF)was prepared by sol–gel method using Ba(CH3COO)2, ZrO(NO3)2 and [CH3(CH2)3O]4Ti as crude materials, La2O3 and Fe2O3 as doping materials, changing the amount of dopant and using different sintering temperatures. The influence of La doping on the crystal structure, micro structure and diffuse ferroelectric phase transition of the sample were investigated. XRD results showed that all samples showed a characteristic peak of a single perovskite type. The appropriate doping amount of La3+ can improve the electrical performance of the sample. With the increase in La content, the degree of lattice distortion of the sample increases, causing the Curie temperature to move toward the low temperature. At the same time, the increase in the degree of dispersion of ferroelectric phase transitions can be attributed to the growth of grains and the reduction of long-range ordered domains. When doped with 0.6 mol% La, the sample has the highest degree of dispersivity ferroelectric phase transition, and the dielectric properties is the best:(ε25℃ = 5680, tanδ = 0.044, Tc = 42℃, γ = 1.89). [ABSTRACT FROM AUTHOR]

The dielectric, piezoelectric properties and dispersive ferroelectric phase transitions of (0.84 − x) BaTiO3–0.16CaTiO3–xBaZrO3 ternary ceramics were investigated in this manuscript. The study found that the optimum BaZrO3 doping amount was 0.1 mol%. Compared to the binary system, the ternary system has a denser microstructure and a more uniform grain size, and more excellent electrical properties. The influence mechanism of BaZrO3 doping on the system was explained in detail by lattice theory and domain theory. [ABSTRACT FROM AUTHOR]

(1-x) K 0.48 Na 0.52 Nb 0.96 Sb 0.04 O 3 - x Bi 0.5 Na 0.5 ZrO 3 [(1-x) KNNS - x BNZ] lead-free piezoelectric ceramics with R(rhombohedral)-T(tetragonal) phase boundary have been successfully synthesized. The influences of Bi 0.5 Na 0.5 ZrO 3 (BNZ) doping on the phase structure, microstructure as well as dielectric properties, piezoelectric properties of the ceramics were systematically studied. It was observed by XRD and ε r - T curve that the R and T phases coexisted in the ceramic samples in the range of 0.03 ≤ x ≤ 0.04. The introduction of BNZ can obviously refine the ceramic grains and improve the density of the ceramics through the observation of the SEM images. In addition, some small nanostructured domains were found in the (1-x) KNNS - x BNZ ceramic when x = 0.03, which can be attributed to the fact that the domain wall energy of the ceramics is in a low state in the R-T phase boundary region, and the optimal values of ε r = 5609, tan δ = 0.035, and d 33 = 278 pC/N were obtained simultaneously. Therefore, we believe that the (1-x) KNNS - x BNZ ceramics can provide a better solution for the application of lead-free piezoelectric ceramics. [Display omitted] • The Bi 0.5 Na 0.5 ZrO 3 promoted the construction of R-T phase boundary in ceramics. • Nano-domains were found in the ceramics with R-T phase boundaries. • The decrease of domain wall energy promotes the formation of nano-domain. • The optimization of ceramics benefits from the R-T phase boundary. [ABSTRACT FROM AUTHOR]

0.96(K 0.48 Na 0.52-x Li x)NbO 3 -0.04Bi 0.5 Na 0.5 ZrO 3 (KNL x N-BNZ) lead-free ceramics have been synthesized by traditional solid-state reaction. Here, the relationship between phase composition and piezoelectric performance of ceramics is explored systematically. Analysis of XRD and Raman spectroscopy confirmed that the orthogonal (O) phase and the tetragonal (T) phase coexisted in each sample at room temperature. By studying the function curve of temperature and dielectric constant ε r , it is found that the introduction of Li+ in ceramics can have a lower O-T phase transition temperature (T O-T) and a higher Curie temperature (T C), with the T O-T closest to room temperature and the highest coexistence volume proportion of O-T phase in the ceramic when x = 0.03, which had the optimum values for d 33 = 252 pC/N and T C = 382 °C. Due to the excellent piezoelectric properties and high T C , it is believed that KNL x N-BNZ piezoceramics can have great application prospects at high temperatures. • 0.96(K 0.48 Na 0.52-x Li x)NbO 3 -0.04Bi 0.5 Na 0.5 ZrO 3 (KNL x N-BNZ) ceramics was successfully synthesized. • The phase transition temperature T O-T and T C of the ceramics were shifted by Li+ doped. • KNL 0.03 N-BNZ ceramic has a lower T O-T and a higher coexistence proportion of O-T phase. • The highest proportion of two phases coexistence is the most efficient. • KNL 0.03 N-BNZ ceramic has a high T C while achieving high piezoelectric performance. [ABSTRACT FROM AUTHOR]