Lu2O3-doped ZnO-Bi2O3-based varistor ceramics samples were prepared by a conventional mixed oxide route and sintered at temperatures in the range of 900-1 000°C,and the microstructures of the varistor ceramics sa...Lu2O3-doped ZnO-Bi2O3-based varistor ceramics samples were prepared by a conventional mixed oxide route and sintered at temperatures in the range of 900-1 000°C,and the microstructures of the varistor ceramics samples were characterized by X-ray diffractometry(XRD)and scanning electron microscopy(SEM);at the same time,the electrical properties and V-I characteristics of the varistor ceramics samples were investigated by a DC parameter instrument for varistors.The results show that the ZnO-Bi2O3-based varistor ceramics with 0.3%Lu2O3(molar fraction)sintered at 950°C exhibit comparatively ideal comprehensive electrical properties.The XRD analysis of the samples shows the presence of ZnO,Bi-rich,spinel Zn7Sb2O12 and Lu2O3-based phases.展开更多
A facile method was developed to synthesize Eu doped LuO(OH) nanorods through hydrothermal processing and Lu2O3 nanorods by subsequent calcining.The microstructural morphologies of the Lu-based nanostructures could be...A facile method was developed to synthesize Eu doped LuO(OH) nanorods through hydrothermal processing and Lu2O3 nanorods by subsequent calcining.The microstructural morphologies of the Lu-based nanostructures could be controlled by simply varying the concentration of NaOH in hydrothermal processing as mineralizer.TEM observation revealed that the obtained LuO(OH) nanorods after hydrothermal processing had a uniform diameter of 10-25 nm and a length around 100 nm.After heat treatment at 600-700°C for 2 h,the high length/diameter ratio was sustained in the obtained Lu2O3 nanorods with different sizes depending on the calcining temperatures.展开更多
Anhydrous lutetium chloride, which is not easy to prepare in other ways, was prepared by chemical vapor transport (CVT) method. Lu2O3 reacted with Al2Cl6 at 300 degrees C to produce LuCl3, which was then separated fro...Anhydrous lutetium chloride, which is not easy to prepare in other ways, was prepared by chemical vapor transport (CVT) method. Lu2O3 reacted with Al2Cl6 at 300 degrees C to produce LuCl3, which was then separated from other solids by means of CVT at a temperature gradient from 400 degrees C to 180 degrees C. Residual Al2Cl6 was removed by dry Cl-2-N-2 gas at 200 degrees C. The purity of the product was > 99.9%.展开更多
A series of energy storage phosphors,Lu2O3:Tb,M(M=Hf,Zr,Ti),were investigated by means of photoand thermoluminescence techniques to compare the effect of the co-dopant from the same group of periodic table of elements...A series of energy storage phosphors,Lu2O3:Tb,M(M=Hf,Zr,Ti),were investigated by means of photoand thermoluminescence techniques to compare the effect of the co-dopant from the same group of periodic table of elements on charge carriers trapping capability and trap parameters.Most of the investigated processes were tracked individually for the Tb3+in the two different metal sites offered by the Lu2O3 host-noncentrosymmetric C2 and centrosymmetric C3i.It is proved that both Tb3+ions participate in hole trapping and electrons are immobilized in traps whose depths are defined by the codopant.Deepest traps,~1.79 eV,appear upon Ti addition,while Zr and Hf generate traps of very similar,~1.40-1.44 eV,depths.The stored energy may be released not only by means of thermal stimulation but also upon the impact of optical photons.Light from the 390-430 nm range of wavelengths was found the most efficient in the latter process.Also deep red radiation of 780 nm releases most of the trapped electrons in Zr/Hf co-doped ceramics but is much less effective in the case of Tb,Ti material.Consistent scheme of electronic levels engaged in charge carriers trapping and subsequent generation of thermoand optically stimulated luminescence was constructed.展开更多
Nickel-metal hydride （Ni/MH） batteries are one of promising batteries for electric vehicle applications, but at high temperature the charge efficiency of nickel electrode is very low. In order to improve the high-te...Nickel-metal hydride （Ni/MH） batteries are one of promising batteries for electric vehicle applications, but at high temperature the charge efficiency of nickel electrode is very low. In order to improve the high-temperature-efficiency of nickel electrode, spherical nickel hydroxide mixed with various ratios of Lu2O3 was used as active material of pasted nickel electrodes. The results of charge/discharge experiments, cyclic voltammetric measurements and XRD characterizations have shown that after addition of Lu2O3, the oxygen evolution overpotcntial is elevated much, the charge efficiency of nickel electrode at high temperature is greatly improved and the content of β-NiOOH phase increases in charged electrodes. In addition, the mixed ratio of Lu2O3 has different effects on high temperature performances of nickel electrode at different charge/discharge currents, 3.5 % is the optimum mixed ratio, and the action of Lu2O3 on high temperature electrochemical behaviors is more apparent when nickel electrodes are charged at small current than large current.展开更多
基金Project(50902061)supported by the National Natural Science Foundation of ChinaProject(2011-22)supported by the State Key Laboratory of Inorganic Synthesis and Preparative Chemistry of Jilin University,China+3 种基金Project(20100471380)supported by the China Postdoctoral Science FoundationProject(J50102)supported by the Leading Academic Discipline Program of Shanghai Municipal Education Commission,ChinaProject(10KJD430002)supported by the Universities Natural Science Research Program of Jiangsu Province,ChinaProject(2010002)supported by the Jiangsu University Undergraduate Practice-Innovation Training Program,China
文摘Lu2O3-doped ZnO-Bi2O3-based varistor ceramics samples were prepared by a conventional mixed oxide route and sintered at temperatures in the range of 900-1 000°C,and the microstructures of the varistor ceramics samples were characterized by X-ray diffractometry(XRD)and scanning electron microscopy(SEM);at the same time,the electrical properties and V-I characteristics of the varistor ceramics samples were investigated by a DC parameter instrument for varistors.The results show that the ZnO-Bi2O3-based varistor ceramics with 0.3%Lu2O3(molar fraction)sintered at 950°C exhibit comparatively ideal comprehensive electrical properties.The XRD analysis of the samples shows the presence of ZnO,Bi-rich,spinel Zn7Sb2O12 and Lu2O3-based phases.
基金supported by the Shanghai Municipal Basic Research Project (Grant No.09JC1406500)Shanghai Academic Disciplines (Grant No.S30107)
文摘A facile method was developed to synthesize Eu doped LuO(OH) nanorods through hydrothermal processing and Lu2O3 nanorods by subsequent calcining.The microstructural morphologies of the Lu-based nanostructures could be controlled by simply varying the concentration of NaOH in hydrothermal processing as mineralizer.TEM observation revealed that the obtained LuO(OH) nanorods after hydrothermal processing had a uniform diameter of 10-25 nm and a length around 100 nm.After heat treatment at 600-700°C for 2 h,the high length/diameter ratio was sustained in the obtained Lu2O3 nanorods with different sizes depending on the calcining temperatures.
文摘Anhydrous lutetium chloride, which is not easy to prepare in other ways, was prepared by chemical vapor transport (CVT) method. Lu2O3 reacted with Al2Cl6 at 300 degrees C to produce LuCl3, which was then separated from other solids by means of CVT at a temperature gradient from 400 degrees C to 180 degrees C. Residual Al2Cl6 was removed by dry Cl-2-N-2 gas at 200 degrees C. The purity of the product was > 99.9%.
基金Project supported by the Polish National Science Centre(NCN)(#UMO-2014/13/B/ST5/01535)preliminary studies supported by Wroclaw Research Centre EIT+within the project The Application of Nanotechnology in Advanced Materials-NanoMat(POIG.01.01.02-02-002/08)co-financed by the European Regional Development Fund(Innovative Economy Operational Program1.1.2)Experiments with synchrotron radiation were performed at DESY-Hasylab Station in Hamburg and were supported by grant #11-20090289 EC
文摘A series of energy storage phosphors,Lu2O3:Tb,M(M=Hf,Zr,Ti),were investigated by means of photoand thermoluminescence techniques to compare the effect of the co-dopant from the same group of periodic table of elements on charge carriers trapping capability and trap parameters.Most of the investigated processes were tracked individually for the Tb3+in the two different metal sites offered by the Lu2O3 host-noncentrosymmetric C2 and centrosymmetric C3i.It is proved that both Tb3+ions participate in hole trapping and electrons are immobilized in traps whose depths are defined by the codopant.Deepest traps,~1.79 eV,appear upon Ti addition,while Zr and Hf generate traps of very similar,~1.40-1.44 eV,depths.The stored energy may be released not only by means of thermal stimulation but also upon the impact of optical photons.Light from the 390-430 nm range of wavelengths was found the most efficient in the latter process.Also deep red radiation of 780 nm releases most of the trapped electrons in Zr/Hf co-doped ceramics but is much less effective in the case of Tb,Ti material.Consistent scheme of electronic levels engaged in charge carriers trapping and subsequent generation of thermoand optically stimulated luminescence was constructed.
文摘Nickel-metal hydride （Ni/MH） batteries are one of promising batteries for electric vehicle applications, but at high temperature the charge efficiency of nickel electrode is very low. In order to improve the high-temperature-efficiency of nickel electrode, spherical nickel hydroxide mixed with various ratios of Lu2O3 was used as active material of pasted nickel electrodes. The results of charge/discharge experiments, cyclic voltammetric measurements and XRD characterizations have shown that after addition of Lu2O3, the oxygen evolution overpotcntial is elevated much, the charge efficiency of nickel electrode at high temperature is greatly improved and the content of β-NiOOH phase increases in charged electrodes. In addition, the mixed ratio of Lu2O3 has different effects on high temperature performances of nickel electrode at different charge/discharge currents, 3.5 % is the optimum mixed ratio, and the action of Lu2O3 on high temperature electrochemical behaviors is more apparent when nickel electrodes are charged at small current than large current.
