Nanophosphor with the nominal composition of Ca0.8 Zn0.2 TiO3 ： Pr3 ＋ , Na^＋ （CZTOPN） was synthesized at relatively low temperature by the sol-gel method. Metal ions were dispersed by citric acid in ethylene glyc...Nanophosphor with the nominal composition of Ca0.8 Zn0.2 TiO3 ： Pr3 ＋ , Na^＋ （CZTOPN） was synthesized at relatively low temperature by the sol-gel method. Metal ions were dispersed by citric acid in ethylene glycol solvent and then react with Ti（OC4H9）4 to form sol and gel. The decomposition process of the precursor, and crystallization and particle size of CZTOPN were examined by thermal analysis （TG-DSC）, powder X-ray diffraction （XRD）, and scan election microscopy （SEM）. Results of TG-DSC and XRD reveal that the composition of Ca0.8 Zn0.2 TiO3 ： Pr3 ＋ , Na^＋ changes with the sintering temperature. SEM data indicate that the diameter of particles is under 50 nm even if the sintering temperature increases to 1000 ℃. In contrast to a solid state reaction, the excitation spectra of samples synthesized by the sol-gel method shift blue about 10 nm and the emission intensity at 617 nm increases significantly.展开更多
M 0.2Ca 0.8TiO 3∶Pr 3+(M=Mg 2+, Sr 2+, Ba 2+, Zn 2+) long persistence red phosphors were prepared by solid state reaction. The influence of the partially replacing Ca 2+ in CaTiO 3 with Mg 2+, Sr 2+, ...M 0.2Ca 0.8TiO 3∶Pr 3+(M=Mg 2+, Sr 2+, Ba 2+, Zn 2+) long persistence red phosphors were prepared by solid state reaction. The influence of the partially replacing Ca 2+ in CaTiO 3 with Mg 2+, Sr 2+, Ba 2+, Zn 2+ on the excitation spectra, the emission spectra and the long persistence properties were studied. The results suggest that certain quantity of Mg 2+, Sr 2+, Ba 2+, Zn 2+ which partially replace Ca 2+ can enhance the luminescent intensity and prolong the afterglow persistence of the samples. The intensity of Mg 0.2Ca 0.8TiO 3∶Pr 3+ is above all of the samples. Take Mg 0.2Ca 0.8TiO 3∶Pr 3+ as the basic sample, the influence of Pr 3+ concentrations (C(Pr 3+)) on the long afterglow properties were also studied. The results suggest that when the C(Pr 3+) is 0.10% (mol fraction) the intensity of the sample is the highest. The excitation spectra of all these samples show broad band spectra ranging from 300～500 nm peaking at about 342 nm. The emission spectra also exhibit a broad band peaking at 613 nm (CaTiO 3∶Pr 3+ is 612 nm). XRD research indicates that the crystalline phases change due to the replacement of divalent metal ions.The research on the thermoluminescence spectra of Mg 0.2Ca 0.8TiO 3∶Pr 3+ indicates that the peak is at 107.35 ℃ and the depth of the trap energy is about 0 852 eV.展开更多
Nb5＋ doped Ca0.8Zn0.2TiO3：Pr3＋ red long afterglow phosphors were synthesized by solid-state reaction methods. X-ray diffraction, photoluminescence spectroscopy and thermally stimulated spectrometry were used to inv...Nb5＋ doped Ca0.8Zn0.2TiO3：Pr3＋ red long afterglow phosphors were synthesized by solid-state reaction methods. X-ray diffraction, photoluminescence spectroscopy and thermally stimulated spectrometry were used to investigate the effects of Nb5＋ content on the crystal characteristics and luminescent properties of Ca0.8Zn0.2Ti1-xNbxO3：Pr3＋ phosphors. The results showed that the addition of a small quantity of Nb5＋ had negligible effect on the crystal characteristics of Ca0.8Zn0.2Ti1-xNbxO3：Pr3＋, but it could change the trapping parameters （the depth of trap, frequency factors and the concentration of trapped charges at t=0） of Ca0.8Zn0.2Ti1-xNbxO3：Pr3＋ phosphors, and then led to the enhance-ment of red fluorescence and phosphorescence at 612 nm originating from 1D2→3H4 transition of Pr3＋. Both of the red fluorescence intensity and afterglow time reached the largest values in the sample of Ca0.8Zn0.2Ti1-xNbxO3：Pr3＋ with x=0.05. The afterglow time of Ca0.8Zn0.2Ti0.95Nb0.05O3：Pr3＋ phosphors lasted for over 24 min （≥1 mcd/m2） when the excited source was cut off.展开更多
文摘Nanophosphor with the nominal composition of Ca0.8 Zn0.2 TiO3 ： Pr3 ＋ , Na^＋ （CZTOPN） was synthesized at relatively low temperature by the sol-gel method. Metal ions were dispersed by citric acid in ethylene glycol solvent and then react with Ti（OC4H9）4 to form sol and gel. The decomposition process of the precursor, and crystallization and particle size of CZTOPN were examined by thermal analysis （TG-DSC）, powder X-ray diffraction （XRD）, and scan election microscopy （SEM）. Results of TG-DSC and XRD reveal that the composition of Ca0.8 Zn0.2 TiO3 ： Pr3 ＋ , Na^＋ changes with the sintering temperature. SEM data indicate that the diameter of particles is under 50 nm even if the sintering temperature increases to 1000 ℃. In contrast to a solid state reaction, the excitation spectra of samples synthesized by the sol-gel method shift blue about 10 nm and the emission intensity at 617 nm increases significantly.
文摘M 0.2Ca 0.8TiO 3∶Pr 3+(M=Mg 2+, Sr 2+, Ba 2+, Zn 2+) long persistence red phosphors were prepared by solid state reaction. The influence of the partially replacing Ca 2+ in CaTiO 3 with Mg 2+, Sr 2+, Ba 2+, Zn 2+ on the excitation spectra, the emission spectra and the long persistence properties were studied. The results suggest that certain quantity of Mg 2+, Sr 2+, Ba 2+, Zn 2+ which partially replace Ca 2+ can enhance the luminescent intensity and prolong the afterglow persistence of the samples. The intensity of Mg 0.2Ca 0.8TiO 3∶Pr 3+ is above all of the samples. Take Mg 0.2Ca 0.8TiO 3∶Pr 3+ as the basic sample, the influence of Pr 3+ concentrations (C(Pr 3+)) on the long afterglow properties were also studied. The results suggest that when the C(Pr 3+) is 0.10% (mol fraction) the intensity of the sample is the highest. The excitation spectra of all these samples show broad band spectra ranging from 300～500 nm peaking at about 342 nm. The emission spectra also exhibit a broad band peaking at 613 nm (CaTiO 3∶Pr 3+ is 612 nm). XRD research indicates that the crystalline phases change due to the replacement of divalent metal ions.The research on the thermoluminescence spectra of Mg 0.2Ca 0.8TiO 3∶Pr 3+ indicates that the peak is at 107.35 ℃ and the depth of the trap energy is about 0 852 eV.
基金Project supported by the National Natural Science Foundation of China (51072128)Key Research Project of Science and Technology of Shanxi (20110321040-01)Program for the Top Young Academic Leaders of Higher Learning Institutions of Shanxi
文摘Nb5＋ doped Ca0.8Zn0.2TiO3：Pr3＋ red long afterglow phosphors were synthesized by solid-state reaction methods. X-ray diffraction, photoluminescence spectroscopy and thermally stimulated spectrometry were used to investigate the effects of Nb5＋ content on the crystal characteristics and luminescent properties of Ca0.8Zn0.2Ti1-xNbxO3：Pr3＋ phosphors. The results showed that the addition of a small quantity of Nb5＋ had negligible effect on the crystal characteristics of Ca0.8Zn0.2Ti1-xNbxO3：Pr3＋, but it could change the trapping parameters （the depth of trap, frequency factors and the concentration of trapped charges at t=0） of Ca0.8Zn0.2Ti1-xNbxO3：Pr3＋ phosphors, and then led to the enhance-ment of red fluorescence and phosphorescence at 612 nm originating from 1D2→3H4 transition of Pr3＋. Both of the red fluorescence intensity and afterglow time reached the largest values in the sample of Ca0.8Zn0.2Ti1-xNbxO3：Pr3＋ with x=0.05. The afterglow time of Ca0.8Zn0.2Ti0.95Nb0.05O3：Pr3＋ phosphors lasted for over 24 min （≥1 mcd/m2） when the excited source was cut off.
