Nanoscale RE^3＋ （RE=Ce, Tb） doped and codoped lutetium pyrosilicate Lu2Si2O7（LPS） phosphors were prepared by using the sol-gel method. Heat treatment was performed in the temperature range from 900 to 1100 ℃. Th...Nanoscale RE^3＋ （RE=Ce, Tb） doped and codoped lutetium pyrosilicate Lu2Si2O7（LPS） phosphors were prepared by using the sol-gel method. Heat treatment was performed in the temperature range from 900 to 1100 ℃. The crystal structure was analyzed by X-ray diffraction （XRD）. The results showed that the β-type structure of LPS was obtained at 1100 ℃. The excitation spectra in the UV and VUV ranges and the emission spectra of the samples were measured at room temperature, and their luminescent properties were studied. The energy transfer from Ce^3＋ to Tb^3＋ in the codoped samples were observed and discussed.展开更多
To improve the corrosion resistance of porous Si3N4 used in the high temperature environments,which contain water vapor and volatile species,porous Si3N4-Lu2Si2O7 composite ceramics were fabricated by a process of oxi...To improve the corrosion resistance of porous Si3N4 used in the high temperature environments,which contain water vapor and volatile species,porous Si3N4-Lu2Si2O7 composite ceramics were fabricated by a process of oxidation bonding and pressureless sintering in flowing N 2 atmosphere at the temperatures lower than 1550 ° C.The pores in ceramics were formed by removing the pore-forming agent（phenolic resin）.SiO2 derived by the oxidation of Si3N4 at 1250 ° C in air reacted with Lu2O3 at various sintering temperatures,leading to the formation of Lu2Si2O7 with excellent oxidation and corrosion resistance.The phase composition,microstructure,and mechanical properties of the porous ceramics depended on the sintering temperatures.Si3N4-Lu2Si2O7 composite ceramics with the porosity of 52% and the pore size of 0.2 μm were obtained by oxidation bonding at 1250 ° C for 1 h and pressureless sintering at 1550 ° C for 2 h using 4 wt pct Lu2O3 additive.展开更多
基金the National Natural Science Foundation of China (50332050)Specialized Research Fund for the Doctoral Program of Higher Education (20060358054)
文摘Nanoscale RE^3＋ （RE=Ce, Tb） doped and codoped lutetium pyrosilicate Lu2Si2O7（LPS） phosphors were prepared by using the sol-gel method. Heat treatment was performed in the temperature range from 900 to 1100 ℃. The crystal structure was analyzed by X-ray diffraction （XRD）. The results showed that the β-type structure of LPS was obtained at 1100 ℃. The excitation spectra in the UV and VUV ranges and the emission spectra of the samples were measured at room temperature, and their luminescent properties were studied. The energy transfer from Ce^3＋ to Tb^3＋ in the codoped samples were observed and discussed.
基金supported by the "Basic Research Fund" of Northwestern Polytechnical University,China (No. W018105)the Fund of the State Key Laboratory of Solidification Processing in Northwestern Polytechnical University, China (No. KB200920)
文摘To improve the corrosion resistance of porous Si3N4 used in the high temperature environments,which contain water vapor and volatile species,porous Si3N4-Lu2Si2O7 composite ceramics were fabricated by a process of oxidation bonding and pressureless sintering in flowing N 2 atmosphere at the temperatures lower than 1550 ° C.The pores in ceramics were formed by removing the pore-forming agent（phenolic resin）.SiO2 derived by the oxidation of Si3N4 at 1250 ° C in air reacted with Lu2O3 at various sintering temperatures,leading to the formation of Lu2Si2O7 with excellent oxidation and corrosion resistance.The phase composition,microstructure,and mechanical properties of the porous ceramics depended on the sintering temperatures.Si3N4-Lu2Si2O7 composite ceramics with the porosity of 52% and the pore size of 0.2 μm were obtained by oxidation bonding at 1250 ° C for 1 h and pressureless sintering at 1550 ° C for 2 h using 4 wt pct Lu2O3 additive.
