This work focuses on fabrication of 80 alumina/(20-x)zirconia/xHA (x = 0.0. 5.0, 10.0 and 15 wt.

Zinc stannate (ZnSnO3) ceramic nanoparticles were synthesized via a sol-gel polymeric technique utilizing polyacrylic acid as a template polymer. The effect of pH during the synthesis process was investigated by preparing the ZnSnO3 nanoparticles at pH 3 and 8. The structural, molecular, morphological, optical, and dielectric properties of the synthesized ZnSnO3 nanoparticles were thoroughly characterized using FTIR, XRD, SEM, and TEM, with optical and dielectric measurements. FTIR and XRD analyses confirmed the phase purity of the synthesized ZnSnO3 nanoparticles, which exhibited an orthorhombic perovskite crystal structure. As observed in the SEM and TEM images, the ZnSnO3 nanoparticles prepared at pH 8 displayed a more defined cubic crystalline morphology, with an average particle size of 128 nm. The optical properties of the ZnSnO3 nanoparticles showed a high absorption edge in the UV region for both pH conditions. The calculated bandgap energies were 3.67 eV for pH 3 and 3.57 eV for pH 8. The dielectric properties at pH 3 and 8 exhibited a low dielectric constant (ε′ = 4 and 5, respectively) and very low dielectric loss (tan δ = 0.1 and 0.06, respectively) at 1 MHz. These exceptional optical and dielectric properties make the prepared ZnSnO3 nanoparticles a promising material for various applications.

The novel calcium titanate-lithium lanthanum titanate doped with zinc oxide (0.10, 0.30, and 0.50 mol. %) ceramic samples were prepared by solid-state reaction route. The phase formation, microstructure, densification, and microwave dielectric properties were investigated. It was found that the doping with zinc oxide led to a decrease in sintering temperature by 25 oC as compared with pure calcium titanate lithium lanthanum titanate due to the liquid phase effect. Also, the calcium titanate lithium lanthanum titanate (10ZCTLLT&30ZCTLLT)) doped with lower zinc oxide (0.10 and 0.30 mol. %) led to higher densification parameter. This was followed by increasing the zinc oxide doping up to (0.50 mol. %) which resulted in a decrease in densification and microwave dielectric properties which may be attributed to increase in porosity and grain growth upon the evaporation of zinc and oxygen vacancy. This led to the increase in dielectric loss (approximate to 10 x 10-4) value with 50ZCTLLT. Hence, the best result of microwave dielectric characteristics was obtained for 0.5CaTiO3-0.5(Li0.5La0.5)TiO3 with (0.10 and 0.30 mol. % ZnO) 10ZCTLLT and 30ZCTLLT ceramic samples sintered at 1175 oC/2h, with low dielectric constant (epsilon r) = 4.4-10.5, very low dielectric loss = 1.07-2.23 x 10-4 and high quality factor (Q x integral) approximate to 59-55 x 104 at 8 GHz. Consequently, they can be used not only in wireless satellite communications technology but also can be used in the fifth-generation telecommunication 5G technology construction.

This work represents the shaping of alumina–zinc oxide (AZ) samples with the direct coagulation casting method. The effect of zinc oxide (0, 10, 20, 30, and 40 wt%) and the firing temperatures on the phase composition, microstructure, physical properties, and mechanical properties of the AZ samples were studied. The effect of titanium oxide (2, 5, and 7 wt%) and the firing temperatures on the phase composition, microstructure, physical properties, and mechanical properties of the AZ sample with 40 wt% of zinc oxide were studied. Furthermore, the optical properties, magnetic properties, and antimicrobial activity were measured. The results indicate that the increase in zinc oxide enhances the formation of zinc aluminate, which has a gahnite phase. Moreover, increasing the zinc oxide increases the apparent porosity and decreases the grain size and bulk density at various firing temperatures. On the other hand, the addition of 5 wt% titanium oxide increases the bulk density to 3.5 g/cm 3 compared to 1.72 g/cm 3 with no titania. The apparent porosity and compressive strength reached 5% and 69.2 MPa after 5 wt% TiO 2 addition; respectively, compared to 59% and 27.2 MPa with no titania addition. The prepared samples show promising optical band gap of 2.98–3.97 eV, a mixed magnetic behavior, and favorable antibacterial activity against E. coli , S. aureus , B. cereus strains.

This work aimed to prepare calcium-doped zinc oxide (ZC) ceramic nanoparticles in this formula (1-x)ZnO–xCaO with (x = 0, 0.10 and 0.90 mol.%) which are effective against the emerging multidrug-resistant Candida auris for the first time to our knowledge using the sol–gel method. Three different calcination temperatures (Tc) (500, 550 and 600 °C) were employed here. The prepared samples were characterized by XRD, SEM, and Zeta sizer. Also, their antimicrobial activity was assessed. All the prepared samples that were calcined at 600 °C showed particle size at nanometer range. All ZC ceramic samples showed negative zeta potential with higher magnitude indicating the stability of the produced nanoparticles. On increasing, calcium oxide doped in ZC10 and ZC90 ceramic samples, the particle size was decreased with regular hexagonal shape in SEM images. Finally, the prepared ZC ceramic nanoparticles exhibited excellent inhibitory activity against the emerging multidrug-resistant C. auris . Additionally, the prepared nanoparticles were active against both gram-positive Staphylococcus auris (ATCC 25923) and gram-negative E. coli (ATCC 25922). Collectively, ZC ceramic nanoparticles can be used to combat the emerged drug-resistant C. auris instead of applying the current antifungal drugs that exhibited minimum activity.

Crystalline structure, morphology, quantitative chemical constitution and dielectric properties of pure cordierite ceramic (CC) bodies and these doped with xCuO in formula MgO(1-x)Al2O3SiO2(x = 0, 0.02, 0.04 and 0.06 wt %), prepared by a conventional solid state ceramic process, were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray fluorescence (XRF) and broadband dielectric spectrometer (BDS), respectively. Experimental results showed that doping with CuO results in lowering sintering temperature, lowering porosity, increasing bulk density and formation of copper magnesium silicate (CuMgSi2O) phase. CuMgSi2O which was formed with the highest content of CuO (0.06 wt %) increases the glassy phase, i.e. crystalline phase decreases of CC. Accordingly, the dielectric properties of CC found to be affected by CuO content. For instance, the permittivity and loss tangent slightly increased upon doping with 0.02 wt % CuO and then considerably decreased for sample doped with 0.06 wt % CuO due to formation of CuMgSi2O phase. Particularly, the loss tangent attained much lower values (0.003 at 25 degrees C) upon doping with 0.06 wt% CuO. Interestingly, such materials of very low loss can be used as candidates for wireless communication systems as well as in several electronic devices.

This work focuses on sintering of EuxMg2−xSiO4 (x = 0.0, 0.01, 0.03, 0.05) forsterite ceramics under different conditions and study their microstructures, physico-mechanical and photoluminescence characteristics. The starting materials were waste silica fume, pure MgO and europium oxide (Eu2O3). The prepared batches were sintered up to 1500°C in the presence or absence of carbon in ambient atmosphere. The presence of carbon helped in reduction of Eu3+ into Eu2+. The effect of sintering conditions and formed phases on the properties of final product were investigated. The results indicated that the specimens sintered without carbon exhibited improved physico-mechanical properties with formation of forsterite and Eu4.67 (SiO4)3O precipitated from the formed liquid phase. While the samples sintered in carbon exhibited lower physic-mechanical properties with formation of forsterite and clinoenstatite. Photoluminescence properties were improved with increasing the amount of added Eu2O3 for all sintered samples. The specimens sintered without carbon exhibited life time higher than those sintered in the presence of carbon.

The crystal structures, phase compositions and the microwave dielectric properties of (1-x)Ca2+TiO3 - x(Na-0.5(1+) Nd-0.5(3+))TiO3 ceramics prepared by the conventional solid state route have been investigated. The formation of solid solution is confirmed in XRD patterns. A specimen using 0.92Ca(2+)TiO(3)-0.08(Na0.51+Nd0.53+)TiO3 (x = 0.08) sintered at 1250 degrees C/2 h possesses an excellent combination of microwave dielectric properties, (epsilon(r)) = 31.8, a maximum (Qxf) value of 2.10(4) at 5 GHz. This may be related to the increase in density as well as the grain morphology, which led to a reduction in the dielectric loss to a value of 0.25.10(-3). It is proposed as a suitable candidate material for small-sized GPS patch antennas.

The microwave dielectric characteristics, microstructure and physical properties of (1−x)CaTiO3−x(Li0.5La0.5)TiO3 (0.08≤x≤0.9) ceramics (abbreviated 92CT-LLT through 10CT-LLT) prepared by conventional solid-state routes were investigated. Increasing the proportion of (Li0.5La0.5)TiO3 compared to CaTiO3 decreased the sintering temperature of ceramic bodies by 50°C, with achievement of optimum density at 1200°C and formation of dense microstructure due to liquid phase development. In the (1−x)CT−xLLT system, the microwave dielectric properties can be effectively controlled by varying the (Li0.5La0.5)TiO3 content to form favourable secondary phase and microstructure. The best combination of microwave dielectric characteristics was obtained in samples of 50CT-LLT ceramic (x = 0.5) sintered at 1200°C/2 h, with dielectric constant εr = 14.1, low dielectric loss = 0.000021 and quality factor Qxf = 364, 524 at 8 GHz.