[en] Highlights: • The crystal structure of Ca_xZn_1−xSn_0.08Ti_1.92Nb₂O₁₀ ceramics were analyzed. • The quantitative determination of Ca_xZn_1−xSn_0.08Ti_1.92Nb₂O₁₀ ceramics were analyzed. • The typical values of ε = 53.09, Qf = 48,000 GHz, τ_f = 21.20 ppm/°C were obtained. -- Abstract: The quantitative determination and the crystal structure of Ca_xZn_1−xSn_0.08Ti_1.92Nb₂O₁₀ ceramics were analyzed by X-ray diffraction, the microwave dielectric properties were investigated. The results showed that the Ca_xZn_1−xSn_0.08Ti_1.92Nb₂O₁₀ ceramics contained three main phases: ZnTiNb₂O₈ phase, Zn_0.15Nb_0.30Ti_0.55O₂ phase and Unknown Columbite-type phase. With the increase of Ca content, the weight fraction of secondary phase Zn_0.15Nb_0.30Ti_0.55O₂ and Unknown Columbite-type phase increased. For ZnTiNb₂O₈, with the substitution of Ca²⁺ for Zn²⁺, the bond valence of Ti-site increased. The variation of distortion of oxygen octahedral was irregular. For Zn_0.15Nb_0.30Ti_0.55O₂, the distortion of oxygen octahedral and the bond valence of Ti-site increased with substitution of Ca²⁺. The increase of Ti-site bond valence led to a harder rattling of Ti cations of the specimens. As a result, the dielectric constant (ε) and the quality factor value (Qf) decreased, the temperature coefficient of resonant frequency (τ_f) moved to the positive direction. The typical values of ε = 53.09, Qf = 48,000 GHz, τ_f = 21.20 ppm/°C were obtained for Ca_xZn_1−xSn_0.08Ti_1.92Nb₂O₁₀ (x = 0.02) specimens sintered at 1120 °C for 6 h. The relative low sintering temperature and high dielectric properties in microwave range make these ceramics promising for application in multilayer ceramic capacitors

[en] Highlights: • BaCu(B₂O₅) is added to the multi-ions doped SrTiO₃ ceramics as sintering aid. • The sintering temperature is decreased from 1300 °C to 1075 °C. • The incorporation of Ba²⁺ into the matrix increases the dielectric constant. • The breakdown strength increases due to the decrease of grain size and porosity. • The dissolution of BCB contributes to the improvement of dielectric properties. -- Abstract: BaCu(B₂O₅) (BCB) was used as sintering aids to lower the sintering temperature of multi-ions doped SrTiO₃ ceramics effectively from 1300 °C to 1075 °C by conventional solid state method. The effect of BCB content on crystalline structures, microstructures and properties of the ceramics was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and dielectric measurements, respectively. The addition of BCB enhanced the breakdown strength (BDS) while did not sacrifice the dielectric constant. The enhancement of BDS should be due to the modification of microstructures, i.e., smaller and more homogeneous grain sizes after BCB addition. The dielectric constant of BCB-doped ceramics maintained a stable value with 1.0 mol% BCB, which was dominated by the combination of two opposite effects caused by the presence of second phases and the incorporation of Cu²⁺ and Ba²⁺, while further increase was owing to the increase of dissolved Ba²⁺ ions when the content of BCB is more than 2.0 mol%. The multi-ions doped SrTiO₃ ceramics with 1.0 mol% BCB addition showed optimal dielectric properties as follows: dielectric constant of 311.37, average breakdown strength of 28.78 kV/mm, discharged energy density of 1.05 J/cm³ and energy efficiency of 98.83%

[en] The characterization of condensed materials is a crucial aspect of materials science. The science underlying this area of research and analysis is interdisciplinary, combining electromagnetic spectroscopy, surface and interface testing methods, physiochemical analysis methods, and more. All of this must be brought to bear in order to understand the relationship between microstructures and larger-scale properties of condensed matter. Characterization of Condensed Matter: An Introduction to Composition, Microstructure, and Surface Methods introduces the technologies involved in the characterization of condensed matter and their many applications. It incorporates more than a decades’ experience in teaching a successful undergraduate course in the subject and emphasizes accessibility and continuously reinforced learning. The result is a survey which promises to equip students with both underlying theory and real experimental instances of condensed matter characterization. Characterization of Condensed Matter readers will also find: - Detailed treatment of techniques including electromagnetic spectroscopy, X-ray diffraction, X-ray absorption, electron microscopy, surface and element analysis, and more. - Incorporation of concrete experimental examples for each technique. - Exercises at the end of each chapter to facilitate understanding. - Characterization of Condensed Matter is a useful reference for undergraduates and early-career graduate students seeking a foundation and reference for these essential techniques.

[en] Highlights: • Ultra-low temperature (90 °C) curable conductive adhesive was obtained. • The conductive adhesive has low resistivity and high adhesion strength. • It's for surface conduction treatment of piezoelectric composite material. - Abstract: Limited by the low thermal resistance of composite material, ultra-low temperature curable conductive silver adhesive with curing temperature less than 100 °C needed urgently for the surface conduction treatment of piezoelectric composite material. An ultra-low temperature curable nano-silver conductive adhesive with high adhesion strength for the applications of piezoelectric composite material was investigated. The crystal structure of cured adhesive, SEM/EDS analysis, thermal analysis, adhesive properties and conductive properties of different content of nano-silver filler or micron-silver doping samples were studied. The results show that with 60 wt.% nano-silver filler the ultra-low temperature curable conductive silver adhesive had the relatively good conductivity as volume resistivity of 2.37 × 10⁻⁴ Ω cm, and good adhesion strength of 5.13 MPa. Minor micron-doping (below 15 wt.%) could improve conductivity, but would decrease other properties. The ultra-low temperature curable nano-silver conductive adhesive could successfully applied to piezoelectric composite material.

[en] Highlights: ► Ceramic system (Mg_1−xZn_x)_1.8Ti_1.1O₄ was composed by conventional solid-state route and its optimal x value (x = 0.05) was confirmed. ► ZnO was added to improve microwave dielectric properties and lower sintering temperature. Superior dielectric properties (ε_r = 15.03, Q × f = 185,000 GHz, τ_f = −45.1 × 10⁻⁶/°C) was achieved with (Mg_0.95Zn_0.05)_1.8Ti_1.1O₄ sintered at 1375 °C. ► The relationship between microstructure and properties of (Mg_1−xZn_x)_1.8Ti_1.1O₄ was investigated. ► CaTiO₃ was added to improve dielectric properties of (Mg_0.95Zn_0.05)_1.8Ti_1.1O₄ and 0.93(Mg_0.95Zn_0.05)_1.8Ti_1.1O₄–0.07CaTiO₃ was achieved for microwave application (ε_r = 18.26, Q × f = 96,060.1 GHz, τ_f = −4.6 × 10⁻⁶/°C). - Abstract: Composite dielectrics, (1 − y)(Mg_1−xZn_x)_1.8Ti_1.1O₄–yCaTiO₃, were prepared by the conventional solid-state route. The results of the X-ray diffraction and field emission scanning electron microscopy (FESEM) indicated the formation of solid solutions. Microwave dielectric properties of the composites were investigated systematically. For (Mg_1−xZn_x)_1.8Ti_1.1O₄ system, superior dielectric properties (ε_r = 15.03, Q × f = 185,000 GHz, τ_f = −45.1 × 10⁻⁶/°C) were achieved with (Mg_0.95Zn_0.05)_1.8Ti_1.1O₄ sintered at 1375 °C. CaTiO₃, as a τ_f compensator, was added to form a temperature-stable ceramic system. For (1 − y)(Mg_0.95Zn_0.05)_1.8Ti_1.1O₄–yCaTiO₃ system, 0.93(Mg_0.95Zn_0.05)_1.8Ti_1.1O₄–0.07CaTiO₃ ceramic sintered at 1375 °C had optimal dielectric properties (ε_r = 18.26, Q × f = 96,000 GHz, τ_f = −4.6 × 10⁻⁶/°C) which satisfied microwave applications in resonators, filters and antenna substrates.

[en] The correlation of crystal structure and microwave dielectric properties for Zn(Ti_1-xSn_x)Nb₂O₈ ceramics were investigated. The Zn(Ti_1-xSn_x)Nb₂O₈ ceramics contained ZnTiNb₂O₈ and an unknown Columbite-type phase. The columbite structure phase with increasing degree of ordering led to decrease of dielectric constant, increase of Qf and τ_f. The ZnTiNb₂O₈ with decreasing cation valence led to increase of τ_f. The typical values were: ε = 30.88, Qf = 43,500 GHz, τ_f = -54.32 x 10^-6/ deg. C.

[en] Searching low sintering temperature material with ultra-high Curie temperature (>800 °C) is urgent to seafloor hydrothermal vents detection. Bi₂WO₆, as the simplest member of the Aurivillius family was improved to possess ultra-high Curie temperature and ultra-high depolarization temperature by experiment at first time. The crystal structure was determined by ab initio and Rietveld refinement calculations. The symmetry group of ultra-high Curie temperature Bi₂WO₆ is Aba₂ (41). The Curie temperatures of Bi_2(1−x)La_2xWO₆ (x = 0, 0.005, 0.01, 0.02, 0.04) with increasing x are 952 °C, 1008 °C, 905 °C, 853 °C, 822 °C, respectively, and depolarization temperatures of them are around 915 °C, 905 °C, 880 °C, 800 °C, and 725 °C, respectively. The typical properties are as follows: Curie temperature T _c = 905 °C, depolarization temperature T _d = 880 °C, mechanical quality factor Q _m = 621.8, d ₃₃ = 17 pC/N, K ₃₃ = 82.01, tan δ = 0.19 × 10⁻² with x value of 0.01. (letter)