CaxBa1-xTiO3 （CBT） fine particles doped with red luminescence center of Pr3＋ ions （Pr： CBT） were successfully synthesized by salt assisted spray pyrolysis （SASP） process. Scanning electronic microscope （SEM）...CaxBa1-xTiO3 （CBT） fine particles doped with red luminescence center of Pr3＋ ions （Pr： CBT） were successfully synthesized by salt assisted spray pyrolysis （SASP） process. Scanning electronic microscope （SEM） and laser scattering analysis demonstrate that salt can be removed from the surface of particles by washing with Milli-Q water and the particles can be further separated by ball-milling to get well-dispersed Pr^3＋ ions doped CBT fine particles. The luminescence properties, such as photoluminescence （PL） and mechanoluminescence （ML）, of as-synthesized Pr： CBT particles were investigated. For Pr： CBT fine particles with different Ca molar ratios, all the samples show one emission at 612 nm, with increasing Ca molar ratio, PL intensity of Pr： CBT fine particles become stronger and stronger. When pressure was loaded on the Pr： CBT pellet, mechanoluminescence（ML） emission was measured. The results show that the ML intensity is proportional to the applied pressure.展开更多
Eu3+ ion-doped LaPO4 nanowires or nanorods have been successfully synthesized by a simple hydrothermal method.The influence of varying the hydrothermal and subsequent sintering conditions on the morphology and structu...Eu3+ ion-doped LaPO4 nanowires or nanorods have been successfully synthesized by a simple hydrothermal method.The influence of varying the hydrothermal and subsequent sintering conditions on the morphology and structure of the LaPO4 host has been investigated by scanning electron microscopy(SEM) and X-ray diffraction(XRD).For comparison,the Eu3+ ions were also doped into monoclinic monazite LaPO4 nanoparticles and perovskite LaAlO3 nanoparticles.The relative intensities of the emission lines of the LaPO4:Eu3+ nanosystems were essentially independent of their shape.The optimal doping concentrations in the monoclinic LaPO4 and perovskite LaAlO3 nanosystems were determined to be about 5.0 and 3.5 mol%,respectively.Under appropriate UV-radiation,the red light emitted from LaAlO3:Eu3+(3.5 mol%) was brighter than that from LaPO4:Eu3+(5.0 mol%) nanomaterial,resulting from differences in their spin-orbit couplings and covalence,which indicates that the nanoscale LaAlO3 is a promising host material for rare earth ions.展开更多
The blue-emitting YPO4 phosphors doped with Yb3＋ were prepared by a simple hydrothermal method. All the products were characterized by XRD and TEM, which revealed that they were zircon structure with leaf-like morpho...The blue-emitting YPO4 phosphors doped with Yb3＋ were prepared by a simple hydrothermal method. All the products were characterized by XRD and TEM, which revealed that they were zircon structure with leaf-like morphology. According to the analysis of photoluminescence spectra, upon ultraviolet （275 nm） excitation, the Yb3＋ doped YPO4 phosphor showed an intense blue emission composed of two main bands at 420 and 620 nm assigned to charge transfer state （CTS） → 2Fs/2 and CTS →ZF7/2, respectively. Moreover, the optimum doping concentration of Yb3＋ in YPO4 phosphor was 1%, which exhibited the maximum emission intensity. The possible physical mechanism of concentration quenching was discussed, and the critical transfer distance determined to be 23.889 A. In particular, the color purity of the as-synthesized Yb3＋ doped YPO4 phosphor was as high as 83%, which made it an excellent candidate for blue-emitting materials.展开更多
基金Funded partly by the Industrial Technology Research Grant Programin ’03 from New Energy and Industrial Technology Development Organization(NEDO) of Japan
文摘CaxBa1-xTiO3 （CBT） fine particles doped with red luminescence center of Pr3＋ ions （Pr： CBT） were successfully synthesized by salt assisted spray pyrolysis （SASP） process. Scanning electronic microscope （SEM） and laser scattering analysis demonstrate that salt can be removed from the surface of particles by washing with Milli-Q water and the particles can be further separated by ball-milling to get well-dispersed Pr^3＋ ions doped CBT fine particles. The luminescence properties, such as photoluminescence （PL） and mechanoluminescence （ML）, of as-synthesized Pr： CBT particles were investigated. For Pr： CBT fine particles with different Ca molar ratios, all the samples show one emission at 612 nm, with increasing Ca molar ratio, PL intensity of Pr： CBT fine particles become stronger and stronger. When pressure was loaded on the Pr： CBT pellet, mechanoluminescence（ML） emission was measured. The results show that the ML intensity is proportional to the applied pressure.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 20873039 & 90606001)Hunan Provincial Natural Science Foundation (No. 07jj4002)the Students Innovation Training Fund of Hunan University
文摘Eu3+ ion-doped LaPO4 nanowires or nanorods have been successfully synthesized by a simple hydrothermal method.The influence of varying the hydrothermal and subsequent sintering conditions on the morphology and structure of the LaPO4 host has been investigated by scanning electron microscopy(SEM) and X-ray diffraction(XRD).For comparison,the Eu3+ ions were also doped into monoclinic monazite LaPO4 nanoparticles and perovskite LaAlO3 nanoparticles.The relative intensities of the emission lines of the LaPO4:Eu3+ nanosystems were essentially independent of their shape.The optimal doping concentrations in the monoclinic LaPO4 and perovskite LaAlO3 nanosystems were determined to be about 5.0 and 3.5 mol%,respectively.Under appropriate UV-radiation,the red light emitted from LaAlO3:Eu3+(3.5 mol%) was brighter than that from LaPO4:Eu3+(5.0 mol%) nanomaterial,resulting from differences in their spin-orbit couplings and covalence,which indicates that the nanoscale LaAlO3 is a promising host material for rare earth ions.
文摘The blue-emitting YPO4 phosphors doped with Yb3＋ were prepared by a simple hydrothermal method. All the products were characterized by XRD and TEM, which revealed that they were zircon structure with leaf-like morphology. According to the analysis of photoluminescence spectra, upon ultraviolet （275 nm） excitation, the Yb3＋ doped YPO4 phosphor showed an intense blue emission composed of two main bands at 420 and 620 nm assigned to charge transfer state （CTS） → 2Fs/2 and CTS →ZF7/2, respectively. Moreover, the optimum doping concentration of Yb3＋ in YPO4 phosphor was 1%, which exhibited the maximum emission intensity. The possible physical mechanism of concentration quenching was discussed, and the critical transfer distance determined to be 23.889 A. In particular, the color purity of the as-synthesized Yb3＋ doped YPO4 phosphor was as high as 83%, which made it an excellent candidate for blue-emitting materials.
