Single phase of Ba1-x MgAl10O17 ： x Eu^2＋ （0.02≤ x ≤ 0. 14） phosphors was first successfully prepared by coprecipitation in aqueous medium with a “reverse strike” method, using oxalic acid and ammonia together...Single phase of Ba1-x MgAl10O17 ： x Eu^2＋ （0.02≤ x ≤ 0. 14） phosphors was first successfully prepared by coprecipitation in aqueous medium with a “reverse strike” method, using oxalic acid and ammonia together as precipitants. Completely crystallized phosphors were obtained at 1300 ℃, which is 300 ℃ lower than the temperature of solid-state reaction. Their photoluminescence was investigated under UV and VUV region, respectively. The emission spectra of Ba1-x MgAl10O17：xEu^2＋ samples excited by 254 or 147 nm showed a characteristic wide band with the peak centred at about 450 454 nm. Optimum emission intensity reached at x = 0.1 and then concentration quenching occurred. The synthesized phosphor shows 10% higher emission intensity than that prepared by solid-state reaction.展开更多
A real high power vacuum ultraviolet light source is applied to the investigation on the vacuum ultraviolet irra- diation degradation of BaMgAl10O17：Eu2＋ phosphor. The degradations of emission intensity and color qu...A real high power vacuum ultraviolet light source is applied to the investigation on the vacuum ultraviolet irra- diation degradation of BaMgAl10O17：Eu2＋ phosphor. The degradations of emission intensity and color quality of the sample are clearly observed after irradiation. It reveals that the oxidation of Eu2＋ during irradiation is partly respon- sible for the degradations. The excitation and absorption spectra show that some traps generated during irradiation have negative influence on the luminescence of sample and these traps have been identified as positively charged oxygen vacancies by positron annihilation. The investigations on host emission and decay curve further confirm that these oxygen vacancies are involved in the perturbation of energy transfer from the host to Eu2＋ and finally result in the degradation.展开更多
Eu 2+-doped BaZnAl 10O 17 phosphor was successfully obtained by coprecipitation method, in which oxalic acid and ammonia were used as precipitants, and precipitates were calcined at 1400 ℃ for 3 h. Its lumin...Eu 2+-doped BaZnAl 10O 17 phosphor was successfully obtained by coprecipitation method, in which oxalic acid and ammonia were used as precipitants, and precipitates were calcined at 1400 ℃ for 3 h. Its luminescent intensity was much stronger than the one obtained by solid-state reaction at high temperature. According to XRD, the crystal was identified as BaZnAl 10O 17 with β-Al 2O 3 structure.展开更多
基金Project supported bythe National Natural Science Foundation of China (50272026) ,the Excellent Young Teachers ProgramofMOE,China (EYTP) and the Natural Science Foundation of Gansu Province (ZS031-A25-033-C)
文摘Single phase of Ba1-x MgAl10O17 ： x Eu^2＋ （0.02≤ x ≤ 0. 14） phosphors was first successfully prepared by coprecipitation in aqueous medium with a “reverse strike” method, using oxalic acid and ammonia together as precipitants. Completely crystallized phosphors were obtained at 1300 ℃, which is 300 ℃ lower than the temperature of solid-state reaction. Their photoluminescence was investigated under UV and VUV region, respectively. The emission spectra of Ba1-x MgAl10O17：xEu^2＋ samples excited by 254 or 147 nm showed a characteristic wide band with the peak centred at about 450 454 nm. Optimum emission intensity reached at x = 0.1 and then concentration quenching occurred. The synthesized phosphor shows 10% higher emission intensity than that prepared by solid-state reaction.
基金Project supported by the National Natural Science Young Foundation of China(Grant No.10904057)the Fundamental Research Funds for Central Universities,China(Grant No.Lzjbky-2011-125)
文摘A real high power vacuum ultraviolet light source is applied to the investigation on the vacuum ultraviolet irra- diation degradation of BaMgAl10O17：Eu2＋ phosphor. The degradations of emission intensity and color quality of the sample are clearly observed after irradiation. It reveals that the oxidation of Eu2＋ during irradiation is partly respon- sible for the degradations. The excitation and absorption spectra show that some traps generated during irradiation have negative influence on the luminescence of sample and these traps have been identified as positively charged oxygen vacancies by positron annihilation. The investigations on host emission and decay curve further confirm that these oxygen vacancies are involved in the perturbation of energy transfer from the host to Eu2＋ and finally result in the degradation.
基金V. ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.51072191）, One Hundred Talents Program of the Chinese Academy of Sciences, the National Basic Research Program of China （No.2012CB922004）, the National Natural Science Foundation of China （No.11105133）, and USTC- NSRL Association Funding （No.KY2060140005）.
文摘Eu 2+-doped BaZnAl 10O 17 phosphor was successfully obtained by coprecipitation method, in which oxalic acid and ammonia were used as precipitants, and precipitates were calcined at 1400 ℃ for 3 h. Its luminescent intensity was much stronger than the one obtained by solid-state reaction at high temperature. According to XRD, the crystal was identified as BaZnAl 10O 17 with β-Al 2O 3 structure.
