Al_2O_3–CaO–SiC-based ceramic composites with four different compositions were sintered at 1700℃ for 3 h in an air furnace. The phase analysis, microstructural characterization, and elemental composition determinat...Al_2O_3–CaO–SiC-based ceramic composites with four different compositions were sintered at 1700℃ for 3 h in an air furnace. The phase analysis, microstructural characterization, and elemental composition determination of the developed composites were performed by X-ray diffraction(XRD), field-emission scanning electron microscopy(FESEM), and energy-dispersive X-ray(EDAX) analysis, respectively. The shrinkage, thermal properties, and electrical resistivity of the composites were also studied. The experimental results showed the effects of adding silicon carbide and calcia to alumina on the thermal, electrical, and shrinkage properties of the resultant composites. Among the four investigated ceramic composites, the one composed of 99 wt% alumina, 0.5 wt% CaO, and 0.5 wt% SiC exhibited the best characteristics for use as a potting material in a dispenser cathode of a microwave tube. The material exhibited slight expansion instead of shrinkage during drying or firing. Other properties of the composite powder, such as its thermal properties and electrical resistivity, were comparable to those of a commercial alumina powder.展开更多
Precursor foam based Co incorporated α-Fe<sub>2</sub>O<sub>3</sub> (AFC) was successfully synthesized at 600℃ calcination temperature by simple solution method using PVA. The formation of α-...Precursor foam based Co incorporated α-Fe<sub>2</sub>O<sub>3</sub> (AFC) was successfully synthesized at 600℃ calcination temperature by simple solution method using PVA. The formation of α-Fe<sub>2</sub>O<sub>3</sub> nanoparticles was confirmed by X-ray diffraction measurement and reduction in crystallite size was found after cobalt incorporation. Field emission scanning electron microscopy revealed the existence of pyramidal shaped iron oxide in AFC. FTIR and Raman spectra also confirmed the presence of α-Fe<sub>2</sub>O<sub>3</sub>. Photocatalytic activity study showed that the cobalt incorporated α-Fe<sub>2</sub>O<sub>3</sub> was better photocatalyst than pure α-Fe<sub>2</sub>O<sub>3</sub>. The cobalt incorporated iron oxide nanoparticles could be used for drug delivery application and this simple preparation method could be adopted for the synthesis of other transition metal oxides.展开更多
基金financial support of Council of Scientific and Industrial Research (CSIR), India Through network Project (No. MTDDC-PSC0101)
文摘Al_2O_3–CaO–SiC-based ceramic composites with four different compositions were sintered at 1700℃ for 3 h in an air furnace. The phase analysis, microstructural characterization, and elemental composition determination of the developed composites were performed by X-ray diffraction(XRD), field-emission scanning electron microscopy(FESEM), and energy-dispersive X-ray(EDAX) analysis, respectively. The shrinkage, thermal properties, and electrical resistivity of the composites were also studied. The experimental results showed the effects of adding silicon carbide and calcia to alumina on the thermal, electrical, and shrinkage properties of the resultant composites. Among the four investigated ceramic composites, the one composed of 99 wt% alumina, 0.5 wt% CaO, and 0.5 wt% SiC exhibited the best characteristics for use as a potting material in a dispenser cathode of a microwave tube. The material exhibited slight expansion instead of shrinkage during drying or firing. Other properties of the composite powder, such as its thermal properties and electrical resistivity, were comparable to those of a commercial alumina powder.
文摘Precursor foam based Co incorporated α-Fe<sub>2</sub>O<sub>3</sub> (AFC) was successfully synthesized at 600℃ calcination temperature by simple solution method using PVA. The formation of α-Fe<sub>2</sub>O<sub>3</sub> nanoparticles was confirmed by X-ray diffraction measurement and reduction in crystallite size was found after cobalt incorporation. Field emission scanning electron microscopy revealed the existence of pyramidal shaped iron oxide in AFC. FTIR and Raman spectra also confirmed the presence of α-Fe<sub>2</sub>O<sub>3</sub>. Photocatalytic activity study showed that the cobalt incorporated α-Fe<sub>2</sub>O<sub>3</sub> was better photocatalyst than pure α-Fe<sub>2</sub>O<sub>3</sub>. The cobalt incorporated iron oxide nanoparticles could be used for drug delivery application and this simple preparation method could be adopted for the synthesis of other transition metal oxides.
