排序方式: 共有49条查询结果,搜索用时 15 毫秒
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hosphorsthatworkunderVUVexcita tion ,asakindofadvancedfunctionalmateri al ,canbeappliedinmercury lessfluores cencelampsandplasmadisplaypanels .Therareearthborates ,withexceptionaldamagethresholdandhighluminescentefficiency ,arepracticalVUVphosphors .However ,… 相似文献
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Bariumtitanate (BaTiO3)isawell knownferro electricmaterial.Comparedtootherferroelectricma terials,suchasLiNbO3,BaTiO3hasmanyadvancedproperties ,forexamplehighelectro opticalindex (r= 82 0pm·V- 1,6 32 8nm ,higherthan 30 8pm·V- 1at 6 32 8nmofLiNbO3) ,lowhalf wavevolt age (310Vat 6 32 8nm ,lowerthan 2 94 0Vat 6 32 8ofLiNbO3) [1] ,lowpropagatinglossofopticalwave(≤ 4± 2dB·cm- 1) [2 ] andconvenientdopingofrare earthions ,whichisnecessaryforopticallyactivede vices .RecentlyBaTiO3fi… 相似文献
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Recentlytherehasbeenanincreasingeffortin thestudyoftheUVandVUV4f→5dspectroscopy ofrareearthions.Knownasanidealmatrixfortri valentrareearthionsandhavingsmallabsorptionin UV,LiYF4(YLF)canbeusedinapplicationofUV solid statelasers[1].Amongmanypossibledopant… 相似文献
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Nanoscaled SrAl12O19:Er3+ and SrAl12O19:Yb3+,Er3+ phosphors were synthesized by a combustion method.The emission intensities of every sample were compared by a new method with the emission of codoped Gd3+ ions as a reference.Compared with their bulk material prepared by the solid-state reaction method,a higher Er3+ quenching concentration,as high as 20%,was observed in the nanoscaled phosphors for both visible(VIS) and near infrared(NIR) emissions.The higher quenching concentration in both VIS and NIR regions for nanoscaled samples are related to the structure characteristics of the nano particles.The influence of the introduction of Yb3+ ions on the emission spectra intensity was also investigated and discussed. 相似文献
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Under 980 nm laser excitation,red emission(5D0-7FJ(J=0,1,2)) of Eu3+ was observed in cubic Y2O3 codoped with Eu3+ and Yb3+.The dependence of the upconverted emission on doping concentration and laser power was studied.Yb3+ emission around 1000 nm(2F5/2-2F7/2) was reported upon excitation of Eu3+ ions.The decay curves of 5DJ(J=0,2) emission of Eu3+ under excitation of 266 nm pulse laser were examined to investigate the Eu3+→Yb3+ energy transfer process.Cooperative energy transfer process was discussed as the possible mechanism for the visible up-conversion luminescence of Eu3+ and near-infrared down-conversion emission of Yb3+. 相似文献
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Synthesis and luminescent properties of Ce~(3+) doped LuAG nano-sized powders by mixed solvo-thermal method 总被引:1,自引:0,他引:1
Polycrystalline LuAG:Ce3+(cerium3+-doped lutetium aluminum garnet) powders were prepared by mixed solvo-thermal method.Fourier-transform IR spectroscopy(FTIR) and X-ray diffraction(XRD) measurements showed that the precursors were ethanol derivatives AlO(OH) crystal with hydroxyl and carbonate group.XRD results showed that phase of Lu2O3 disappeared with the precursors were annealed at 400 °C,cubic phase LuAG:Ce3+ appeared but only one diffraction peaks of LuAP(LuAlO3) at calcination temperature to 700 °C,and the purified crystalline phase of LuAG:Ce3+ was obtained at 1000 °C.The scanning electron microscopy(SEM) analysis revealed that the synthesized LuAG:Ce3+ powders were uniform and had good dispersivity with an average particle size about 100 nm.Excitation and emission spectra of Ce3+ doped LuAG phosphors were measured.Many factors of affecting the intensity of emission spectra were discussed. 相似文献
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尹民 《中国稀土学报(英文版)》2004,22(1):22-26
Crystals of LiKGdF5:Er^3 , Tb^3 grown by the hydrothermal synthesis technique with concentrations of 2% and 0.4% were analysed. By using site selective excitation measured at low temperature, luminescence and excitation spectra from Er^3 and Tb^3 ions embedded in LiKGdF5 were clearly separated. The lifetimes of the emitting levels ^4S3/2 of Er^3 and ^5D4 of Tb^3 were also determined. Following the site selective spectroscopy study, the dominant energy transfer process from Tb^3 to Er^3 in the crystal was then investigated via transient experiments. 相似文献
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Nanocrystalline monoclinic and cubic Gd2O3:Eu with different Eu^3 concentration were prepared using glycinenitrate combustion synthesis. By changing the ratio of glycine to nitrate and proper heat treatment, pure monoclinic and cubic Gd203:Eu with particle size less than 40 nm can be easily formed. Under ultraviolet excitation, main emission of Eu^3 (^5D0→^7F2) locates at 624 nm in monoclinic Gd2O3:Eu and 611 nm in cubic sample, In excitation spectrum two broad bands corresponding to the host absorption and charge transfer state (CTS) and f-f transitions of Gd^3 and Eu^3 were observed and discussed. The quenching concentration of monoclinic and cubic Gd2O3:Eu is 10% and 15 %, respectively,both of which are much higher than that of bulk Gd2O3 : Eu. 相似文献
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采用脉冲激光沉积方法(PLD)在Si(100)衬底上生长了HfO2栅介质薄膜.利用X射线衍射(XRD)和扩展X射线吸收精细结构(EXAFS)对其结构进行了表征,利用远红外光谱对其声子振动模式和介电性质进行了研究.结果表明,室温下制备薄膜为非晶,衬底温度400℃时已经形成单斜相的HfO2薄膜,1000℃退火后薄膜更趋向于(1-11)晶面取向,且结晶质量改善.薄膜的局域结构研究显示低衬底温度下生长的样品具有更短的Hf-O键长和更高的无序度.薄膜结构和薄膜质量影响其远红外声子模式,使得一些低频红外声子模式消失,造成其介电常数相对体材料有所降低,但由于影响介电常数的主要远红外声子模式依然存在,晶态薄膜仍然能保持一定的介电常数值. 相似文献