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Microwave dielectric properties and microstructures of (Ca0.8Sr0.2)ZrO3 ceramics prepared by the conventional solid-state route have been studied. The values of the dielectric constant (εr) were 22-26. The Q×f values of 10400–11500 GHz were obtained when the sintering temperatures were in the range of 1400–1490°C. The temperature coefficient of the resonant frequency τf was not sensitive to the sintering temperature. The εr value of 26, the Q×f value of 11500 GHz, and the τf value of-9 ppm/°C were obtained for (Ca0.8Sr0.2)ZrO3 ceramics sintering at 1490°C. The ceramic, (Ca0.8Sr0.2)ZrO3 is proposed as a suitable candidate material for application in highly selective microwave ceramic passive components.

The compositions, electrical properties and microstructures of zinc oxide ceramics with various 46.6ZnO-20Na2O-33.4P2O5 glass oxide additions prepared by solid-state method have been investigated. The structure of the materials is studied using X-Ray diffraction, and the microstructure is analyzed using scanning electron microscopy. The results indicated that the electrical properties were associated with the amount of 46.6ZnO-20Na2O-33.4P2O5 glass oxide additions and the sintering temperatures. The correlation between the microstructures, oxide additions and the sintering temperature was also discussed. From the results of electrical properties measurements, zinc oxide ceramics with various 46.6ZnO-20Na2O-33.4P2O5 glass oxide additions exhibits a good electrical behavior, which can be a suitable candidate material for electronic device applications.

The microstructure and dielectric properties of the (Ca0.3Sr0.1)Sm0.4TiO3 ceramics with various sintering conditions have been investigated. The compounds were prepared by the conventional solid-state route with various sintering temperatures from 1340 to 1400°C and sintering duration from 3 h. The resultant microwave dielectric properties were analyzed based upon the densification, the X-ray diffraction patterns and the microstructures of the ceramics. The correlation between the microstructures, the microwave dielectric properties and sintering behaviors was also examined. The εr value of 96.7 and Q×f value of 11,600 GHz were obtained for (Ca0.3Sr0.1)Sm0.4TiO3 ceramics sintering at 1370°C for 3 h. The (Ca0.3Sr0.1)Sm0.4TiO3 ceramics had suitable dielectric properties can find applications in microwave devices such as resonator, filter and antenna.

The physical and optical properties of P2O5-Al2O3-ZnO glasses doped with different concentration of Yb3+ ions were investigated. The experimental results indicated that density, chemical durability, glass transition temperature (Tg) and glass softening temperature (Td) of glasses increase with increasing the Yb2O3 content of glasses. However, the coefficient of thermal expansion (α) for glasses decrease with increasing the Yb2O3 content. From the results of Fourier transform infrared spectroscopy, the numbers of (-P-O-P-) bonds decrease and (-P-O-M+-) bonds increase with increasing the Yb2O3 content. Increase of non-bridge oxygen (-P-O-M+-) raise the refractive index of glasses. Moreover, the results of absorption spectra indicate that the absorption peak of glasses are observed at both wavelengths of 916nm and 977nm. As increasing the concentration of Yb2O3, the absorption efficiencies become stronger. In accordance with the results of fluorescence spectra, the fluorescence emission of glasses are detected at wavelengths of 970nm, 995nm, 1020nm and 1048nm, respectively. The intensity of the fluorescence emission peaks significantly decrease at wavelengths of 970nm and 995nm as the concentration of Yb2O3 increases. However, the intensity of the fluorescence emission peaks significantly increase at wavelength of 1048nm under the same condition.

Microwave dielectric properties of BaTi5O11 ceramics prepared by solid-state method with various calcining temperatures and sintering temperatures have been discussed. The εr value of 42.8, the Q×f value of 44,000 GHz, and the τf value of 42.4 ppm/oC were obtained for BaTi5O11 ceramics sintering at 1100oC for 4 h. BaTi5O11 is proposed as a suitable material candidate for application in high selective microwave ceramic passive components.

The electrical properties and microstructures of ZnO-doped Nd(Co1/2Ti1/2)O3thin films prepared by rf-magnetron sputtering on indium tin oxide (ITO)/glass substrates at different rf powers and Ar/O2ratios have been investigated. X-ray diffraction pattern analysis showed that the deposited films exhibited a polycrystalline microstructure. All films exhibited the ZnO-doped Nd(Co1/2Ti1/2)O3orientation perpendicular to the substrate surface, and the uniformity of surface morphologies of the film increased with decreasing Ar partial pressure and rf power. At an Ar/O2ratio of 80/20 and a rf power of 250 W, the ZnO-doped Nd(Co1/2Ti1/2)O3films possess a dielectric constant of 28.6 at 1 kHz, a dissipation factor of 0.02 at 1 kHz, and a leakage current density of $3.6\times 10^{-10}$ A/cm2at an electrical field of 20 kV/cm.

The microwave dielectric properties of (Ca0.2Sr0.8)3Ti2O7 ceramic system have been investigated with various pressure conditions. The compounds were prepared by the conventional solid-state route with various pressure conditions from 60 to 80 Kg/cm2 and sintered at 1450oC for 4 h. The structure and microstructure were analyzed using X-ray diffraction and scanning electron microscopy techniques. The (Ca0.2Sr0.8)3Ti2O7 had excellent dielectric properties: Q×f ~ 50,000 (GHz) and εr ~ 63.2 for the sample at 70 Kg/cm2.

The microstructure and dielectric properties of the complex perovskite Nd(Col/2Ti1/2)03 ceramics with 60P2O5-15ZnO-5La2O3-5Al2O3-5N2O-5MgO-5Yb2O3 glass additions from 1-2 wt% were prepared with the conventional solid-state route have been investigated. The resultant microwave dielectric properties were analyzed based upon the densification, the X-ray diffraction patterns and the microstructures of the ceramics. Doping with 60P2O5-15ZnO-5La2O3-5Al2O3- 5N2O-5MgO-5Yb2O3 glass (up to 2 wt%) can effectively promote the densification of Nd(Co1/2Ti1/2)O3 ceramics at low sintering temperature. A distinct sintering temperature reduction (100-200°C) can be achieved by adding 60P2O5-15ZnO-5La2O3-5Al2O3-5N2O-5MgO-5Yb2O3 glass to the Nd(Co1/2Ti1/2)O3 ceramics. The correlation between the microstructures and the microwave dielectric properties was also examined. The Nd(Co1/2Ti1/2)O3 ceramics with 60P2O5-15ZnO-5La2O3- 5Al2O3-5N2O-5MgO-5Yb2O3 glass additions can find applications in microwave devices requiring low sintering temperature.

Microstructure, optical and electrical properties of ZnO-doped (Zr0.8Sn0.2)TiO4 thin films prepared by rf magnetron sputtering on ITO/Glass substrates at different argon-oxygen (Ar/O2) mixture have been investigated. The surface structural and morphological characteristics analyzed by X-ray diffraction (XRD) and atomic force microscope (AFM) were found to be sensitive to the Ar/O2 ratio. Optical transmittance spectroscopy further revealed high transparency (over 70%) in the visible region of the spectrum. At an Ar/O2 ratio of 100/0 and a substrate temperature of 400°C, the ZnO-doped (Zr0.8Sn0.2)TiO2 films possess a dielectric constant of 44 at 10 MHz, a dissipation factor of 0.03 at 10 MHz, a leakage current density of 3.73×10-9 A/cm2.

This paper describes microstructure characteristics of MgAl2O4 thin films were deposited by sol-gel method with various preheating temperatures and annealing temperatures. Particular attention will be paid to the effects of a thermal treatment in air ambient on the physical properties. The annealed films were characterized using X-ray diffraction. The surface morphologies of treatment film were examined by scanning electron microscopy and atomic force microscopy. At a preheating temperature of 300oC and an annealing temperature of 700oC, the MgAl2O4 films with 9 μm thickness possess a dielectric constant of 9 at 1 kHz and a dissipation factor of 0.18 at 1 kHz.

The microstructure properties of the perovskite Bi0.5Na0.5TiO3-BaZrO3 ceramics were prepared with the conventional solid-state route have been investigated. The resultant microstructure properties were analyzed based upon the densification, the X-ray diffraction patterns and scanning electron microscopy. The correlation between the microstructures and the sintering temperature was also examined.

The microwave dielectric properties and microstructures of an Mg(Zr0.05Ti0.95)O3 ceramic system have been investigated. The compounds were prepared by the conventional solid-state route with various pressure conditions from 25 to 100 Kg/cm2 and sintered at 1420oC for 4 h. The structure and microstructure were analyzed using X-ray diffraction and scanning electron microscopy techniques. The Mg(Zr0.05Ti0.95)O3 had excellent dielectric properties: Q×f ~ 194,000 (GHz), εr ~ 17.9, and τf ~ -43 ppm/oC for the sample at 90 Kg/cm2.

Electrical and optical properties of 1wt% ZnO-doped (Zr0.8Sn0.2)TiO4 thin films prepared by rf magnetron sputtering on ITO/Glass substrates at different rf power and substrate temperature were investigated. The surface structural and morphological characteristics analyzed by X-ray diffraction (XRD) and atomic force microscope (AFM) were found to be sensitive to the deposition conditions, such as rf power and substrate temperature. The selected-area diffraction pattern showed that the deposited films exhibited a polycrystalline microstructure. All films exhibited ZST (111) orientation perpendicular to the substrate surface and the grain size as well as the deposition rate of the film increased with the increase in both the rf power and the substrate temperature. Optical transmittance spectroscopy further revealed high transparency (over 60%) in the visible region of the spectrum.

This paper describes microstructure characteristics of MgAl2O4 thin films were deposited by sol-gel method with various annealing temperatures. Particular attention will be paid to the effects of an annealing treatment in air ambient on the physical properties. The annealed films were characterized using X-ray diffraction. The surface morphologies of annealed film were examined by scanning electron microscopy and atomic force microscopy. The dependence of the dielectric properties and microstructure characteristics on annealing temperature was also investigated.

CeO2 ceramics with ZnO additions (1 and 2 wt%) were prepared with conventional solid-state route have been investigated. Doping with ZnO (up to 1 wt%) can effectively promote the densification of CeO2 ceramics at low sintering temperature. At 1550 oC, CeO2 ceramics with 1 wt% ZnO addition possesses a dielectric constant ( ε r) of 23.2, a Q×f value of 53000 GHz and a temperature coefficient of resonant frequency (τf) of –47 ppm/oC.

This paper describes microstructure and leakage current characteristics of ZrTiO4 thin films on ITO/Glass substrate were deposited by sol-gel method with a fix per-heating temperature of 250oC for 30min at various annealing temperatures from 600oC to 800oC for 1 hr. The annealed films were characterized using X-ray diffraction. The surface morphologies of annealed film were examined by atomic force microscopy. The dependence of the microstructure and leakage current characteristics on annealing temperature was also investigated.