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Textured relaxor-PbTiO3 ceramics have received considerable attention from both academia and industry, due to their crystal-like properties, high composition homogeneity easy-to-process, and relatively low cost compared to their crystal counterparts. In this work, the ⟨ 001 ⟩ -oriented Pb(In1/2Nb1/2)O3-Pb(Sc1/2Nb1/2)O3-PbTiO3 textured ceramics were fabricated by the template grain growth method. To explore the property variation in these textured ceramics under practical applications of piezoelectric devices, their electromechanical properties were characterized and analyzed under uniaxial stress, hydrostatic pressure, and d.c. bias electric field. The results show that the dielectric constants of all textured ceramics increase with an increase in the uniaxial prestress and hydrostatic pressure but decrease with an increase in the d.c. bias electric field. Among all textured ceramics, the textured ceramic with 3 vol. % BT templates exhibits the best stability under external fields. In particular, the electromechanical coupling factors of the textured ceramic change less than 2% with the hydrostatic pressure increase to 100 MPa. This work provides important data on textured relaxor ferroelectric ceramics, which will benefit the design and application of piezoelectric devices based on textured piezoelectric ceramics. [ABSTRACT FROM AUTHOR]

Textured relaxor-PbTiO3 (PT) ceramics possess advantages of crystal-like properties, high composition homogeneity, and low cost, and have, thus, received considerable attention from the piezoelectric community. To promote the applications of textured relaxor-PT ceramics, here we characterize the full electromechanical parameters (elastic, dielectric, and piezoelectric coefficients) and the frequency dependence of the coercive field (EC) for the recently reported textured Pb(In1/2Nb1/2)O3-Pb(Sc1/2Nb1/2)O3-PbTiO3 (PIN-PSN-PT) ceramic. Our results show that the textured PIN-PSN-PT ceramic possesses high piezoelectric coefficients (d31 = −365 pC N−1, d33 = 770 pC N−1, and g33 = 40.4 × 10−3 m2 C−1) and electromechanical coupling factors (k33 = 87% and kp = 82%), far outperforming those of the commercial ceramic PZT-5H (d31 = −274 pC N−1, d33 = 593 pC N−1, g33 = 1.97 × 10−2 m2 C−1, k33 = 75%, and kp = 65%). In addition, the textured PIN-PSN-PT ceramic exhibits lower dielectric constants (ɛ33S = 478) compared with PZT-5H and relaxor-PT crystals, which can greatly promote the sensitivity of receiving transducers. Moreover, the textured PIN-PSN-PT ceramic with a high Tr−t (172 °C) shows better thermal stability compared to commercial relaxor-PT crystals (Tr−t < 130 °C). The results presented here will benefit the development of piezoelectric devices made of textured ceramics. [ABSTRACT FROM AUTHOR]

Modified BaTiO3 ceramics that possess high dielectric permittivity and acceptable temperature stability have been widely utilized as multilayer ceramic capacitors (MLCCs) for high‐frequency bypass and power filtering in automotive applications. However, since the increasing demand for high‐capacity and small‐size, high‐permittivity materials that can serve as dielectric layers in MLCCs are urgently required. In this work, we design and fabricate a special BaTiO3‐0.03Mg‐0.02Y‐0.02CaZrO3 ceramic with a high dielectric permittivity of 3000 and the dielectric variation below ±13% in the temperature range of ‐55–150°C, fulfilling the requirements of X8R capacitors. To achieve these results, we employed grain size engineering and cation doping, using BaTiO3 precursors with a particle size of 240 nm to prepare the BaTiO3‐based ceramics with fine grains, while Mg and Y co‐doping was used for improving the temperature stability due to dielectric dispersion. Utilizing these high‐permittivity BaTiO3‐based materials, we fabricated MLCCs that satisfy the X8R criterion, possessing a high dielectric constant of 2950 and a high breakdown field (410 kV/cm). [ABSTRACT FROM AUTHOR]

In this study, we prepared a series of Nb-doped SrTiO 3 ceramics sintered in both air and N 2 atmospheres. The X-ray diffraction (XRD) analysis indicated that all samples had a pure cubic phase perovskite structure with no secondary phase. The dielectric test showed that the Nb-doped SrTiO 3 ceramics had a high dielectric permittivity (>3 × 104) and low dielectric loss (<0.004) over a broad temperature range from −100 to 300 °C with a breakdown strength over 20 kV/cm. The dielectric performance is attributed to the designated T i T i ′ − V O · · − T i T i ′ deep-lattice-defect states localising weak-hopping electrons to generate high defect-dipole concentrations, as verified by systematic X-ray photoelectron spectroscopy (XPS) experiments. This study offers a route for designing other types of high dielectric permittivity ceramics. • Synthesized a novel Nb-doped SrTiO 3 ceramics with dense and fine-grained microstructure. • Achieved giant permittivity of 3 × 104 and low loss (<0.004) at room temperature. • The designated deep-lattice-defect states localize weak-hopping-electrons to generate high defect-dipoles concentration. [ABSTRACT FROM AUTHOR]

Cold sintered, Li2MoO4‐based ceramics have recently been touted as candidates for electronic packaging and low temperature co‐fired ceramic (LTCC) technology but MoO3 is an expensive and endangered raw material, not suited for large scale commercialization. Here, we present cold sintered temperature‐stable composites based on LiMgPO4 (LMP) in which the Mo (and Li) concentration has been reduced, thereby significantly decreasing raw material costs. Optimum compositions, 0.5LMP‐0.1CaTiO3‐0.4K2MoO4 (LMP‐CTO‐KMO), achieved 97% density at <300°C and 600 MPa for 60 minutes. Raman spectroscopy, X‐ray diffraction, scanning electron microscopy, and energy dispersive X‐ray mapping confirmed the coexistence of end‐members, LMP, CTO, and KMO, with no interdiffusion and parasitic phases. Composites exhibited temperature coefficient of resonant frequency ~ –6 ppm/°C, relative permittivity ~9.1, and Q × f values ~8500 GHz, properties suitable for LTCC technology and competitive with commercial incumbents. [ABSTRACT FROM AUTHOR]

Materials with colossal dielectric permittivity (CP) are in the focus of interest for the development of miniaturization and integration of electronic components. Despite the extensive study of these new classes of co-doped TiO 2 CP materials, the preparation of multilayer ceramics using this kind of CP materials is still challenging work. Here, we synthesize a series of (Sb5+, Nb5+) and (Sm3+, Y3+) co-doped Ti 0.9 Zr 0.1 O 2 ceramics (SNSYTZO) through the conventional solid-state reaction method. XRD spectrum identifies that ceramics under x = 0.04 show a perfect rutile phase with the tetragonal crystal structure; however, minor brookite orthorhombic crystal structure appears when x > 0.04. FESEM images show the prepared ceramics have excellent densification and low porosity. Dielectric, modulus, and impedance spectrum are systematically explored the underlying CP mechanism and compared with each other to find the optimal materials composition to prepare further multilayer ceramics, which is fabricated by the industrial tape casting method. FESEM, together with surface element mapping, indicates that all doping elements are homogeneously distributed. Also, we investigate the dielectric response without/with DC bias. This work sheds light on a promising feasible route to prepare the miniaturization of the next-generation electronics via a large scale industrial tape casting method. [ABSTRACT FROM AUTHOR]

Dielectric materials with high permittivity and low dielectric loss have a range of promising applications within electronic devices. Here, we report on Zr co-doped (Ga 0.5 Nb 0.5) 0.03 Ti 0.97 O 2 ceramics, fabricated using a solid-state reaction. The colossal permittivity (CP) of (Ga 0.5 Nb 0.5) 0.03 -(Zr x Ti 1-x) 0.97 O 2 ceramics was investigated (x = 0%, 1%, 4%, 6%, 10%, 20%). When the doping value of Zr was 4%, the dielectric loss was reduced to 0.098 and, at room temperature and at a frequency of 1000 Hz, the dielectric permittivity was recorded as 2420. In addition, the material's dielectric permittivity exhibited good stability at temperatures ranging from −50 °C to 200 °C. Using X-ray photoelectron spectroscopy (XPS) and Scanning electron microscopy (SEM), we have observed that Zr doping reduces grain size and increases grain boundary regions. According to our XPS and impedance analysis, Zr doping also reduces the concentration of oxygen vacancies, which are considered to be the main cause of dielectric loss. We believe that the Zr doping is an effective method for reducing the dielectric loss of CP materials. [ABSTRACT FROM AUTHOR]

(Nb + In) co-doped rutile TiO 2 (TINO) ceramics have received considerable attention, due to their high dielectric permittivity (on the order of 10,000) and low loss factor (<0.05) over a broad temperature/frequency range. The high dielectric permittivity of TINO has been attributed to a special defect-dipole structure. Here, we observed a similar dielectric behavior in hydrogen-reduced rutile TiO 2 crystals, where the colossal dielectric permittivity of ∼30,000 and the low loss factor of ∼0.05 exist in the temperature range of 30–480 K (frequency at 10∼10 5 Hz). Based on the investigations on the phase microstructures, the elemental valences, impedance spectroscopy, nonlinear I–V behavior and dielectric response, the colossal dielectric permittivity of the hydrogen-reduced rutile TiO 2 crystals was thought to be associated with the electronic relaxation polarization mechanism. This research further revealed that the weak-binding electron is the most critical factor for the high dielectric permittivity in rutile TiO 2 system, while a special defect-dipole structure may not be a preliminary requirement. [ABSTRACT FROM AUTHOR]

The new (Nb+In) co-doped TiO 2 ceramics recently stimulated considerable attention due to their colossal permittivity (CP) (~100,000). In this research, the 3 mol% (Nb+In) co-doped TiO 2 ceramics were synthesized by an standard solid-state reaction method. Phase structure was studied by XRD and Raman, which showed that all samples were in pure rutile phase. The elements distribution was tested by the SEM–EDS, indicating that the Nb and In ions were homogeneously distributed in the grain and grain boundary. Dielectric properties and I – V behavior analysis demonstrated that the ceramics may compose of semiconducting grains and insulating grain boundaries. The existence of CP and nonlinear I – V behavior in sample had been explained by an internal barrier layer capacitance (IBLC) model, which consists of n-type semiconductor grains and insulating grain boundaries. [ABSTRACT FROM AUTHOR]

Recently, colossal permittivities (~10 5 ) and low loss factors (<0.1) were reported in (Nb+In) co-doped rutile TiO 2 ceramics, which have attracted considerable attention. In this work, (Nb,In,B) co-doped rutile TiO 2 ceramics were investigated for achieving temperature- and frequency- stable dielectric properties in TiO 2 based colossal dielectric ceramics. The (Nb,In,B) co-doped rutile TiO 2 ceramics were prepared by conventional solid-state reaction method. The microstructures, dielectric properties and complex impedance of 1 mol.% (Nb+In) co-doped rutile TiO 2 (TINO) and xwt% B 2 O 3 (x=0.5, 1, 2 and 4) doped TINO were systematically investigated and compared. It was found that by doping B 2 O 3 the sintering temperature of TINO ceramics can be reduced by 100 °C. Meanwhile, the dielectric loss of TINO ceramics was decreased by doping B 2 O 3 . In the 2 wt% B 2 O 3 doped TINO ceramics, the dielectric permittivity kept a high value of >2.0×10 5 and the dielectric loss was lower than 0.1 in a frequency range of 10 2 −10 5 Hz and a temperature range of 25–200 °C. [ABSTRACT FROM AUTHOR]

Nb5+ and Ga3+ co-doped Ti 0.9 Zr 0.1 O 2 ceramics were synthesized using the conventional solid-state reaction method. Single rutile-liked phase of octahedron structure were identified for all compositions in (Nb 0.5 Ga 0.5) x (Ti 0.9 Zr 0.1) 1-x O 2 (NGT) with x = 0.01 to 0.10 by X-ray diffraction patterns coupled with Rietveld refinement. Microstructural scanning image, together with energy dispersive x-ray spectroscopy (EDX), revealed good chemical homogeneity in NGT samples. A giant dielectric permittivity of 5 × 104 and a low loss of 0.02 was obtained in NGT with x = 0.01 due to the contribution of electron-pinned and defect-dipole effect. Furthermore, a temperature (-20–120 °C), frequency (0.1–104 Hz) and bias electric field (100–200 V/mm) independent dielectric permittivity and loss was found in this composition, which is critical for potential applications of supercapacitors. [ABSTRACT FROM AUTHOR]