采用高温固相法合成了La_(2)MgTiO_(6)∶Mn^(4+)、La_(2)MgTiO_(6)∶Pr^(3+)、La_(2)MgTiO_(6)∶Pr^(3+),Mn^(4+)单掺杂和双掺杂荧光粉,并通过X射线衍射、扫描电镜、荧光光谱等测试方法对荧光粉的物相结构、形貌和发光特性进行了表征及...采用高温固相法合成了La_(2)MgTiO_(6)∶Mn^(4+)、La_(2)MgTiO_(6)∶Pr^(3+)、La_(2)MgTiO_(6)∶Pr^(3+),Mn^(4+)单掺杂和双掺杂荧光粉,并通过X射线衍射、扫描电镜、荧光光谱等测试方法对荧光粉的物相结构、形貌和发光特性进行了表征及分析。结果表明:成功合成了La_(2)MgTiO_(6)∶Mn^(4+)、La_(2)MgTiO_(6)∶Pr^(3+)、La_(2)MgTiO_(6)∶Pr^(3+),Mn^(4+)荧光粉且均为纯相;样品的粒径为1~2μm;La_(2)MgTiO_(6)∶Mn^(4+)在650~750 nm的红光发射是来自Mn^(4+)的2 E 1→4 A 2跃迁,La_(2)MgTiO_(6)∶Pr^(3+)在红光区域600~660 nm具有强烈的发射,归属为Pr^(3+)的3 P 0→3 H 6和3 P 0→3 F 2跃迁。当Mn^(4+)与Pr^(3+)共同掺杂于La_(2)MgTiO_(6)时,来自Mn^(4+)、Pr^(3+)不同波段的红光发射使荧光粉的发射光谱与植物光敏色素P r与P fr吸收光谱的重叠程度大幅增加,表明Mn^(4+)、Pr^(3+)共掺有效拓宽了La_(2)MgTiO_(6)荧光粉的红光发射区域,更符合植物照明的需求,在LED植物照明领域具有更明显的潜在应用价值。展开更多
The vacuum ultraviolet (VUV) spectroscopic properties of praseodymium (Pr3+, 1at%) doped LaF3 nanocrystals/glass at room temperature and 20 K are reported. Two types of Pr3+ ions, those in LaF3 nanocrystals and those ...The vacuum ultraviolet (VUV) spectroscopic properties of praseodymium (Pr3+, 1at%) doped LaF3 nanocrystals/glass at room temperature and 20 K are reported. Two types of Pr3+ ions, those in LaF3 nanocrystals and those in the glass host, were excited to 4f 5d band by VUV using synchrotron radiation as an excitation source, and emissions of 1S0 → 1D2 (336 nm), 1S0 → 1I6 (397 nm ) of Pr3+ in the nanocrystals and emissions of 4f 5d → 3HJ, 3FJ of Pr3+ in the glass appeared at the same time. But unlike in the bulk sample crystals, emission of 3P0 → 3HJ, 3FJ as the second step of the quantum splitting (QS) of Pr3+ in the LaF3 nanocrystals was not observed at room temperature, which could be explained that Pr3+ ions in the glass absorbed the energy of 3P0 → 3H4 of Pr3+ in the nanocrystals. Two types of excitation spectra monitoring different emissions were also measured, so it could be observed that the lowest energy of 4f 5d band of Pr3+ in the nanocrystals was about 53 500 cm-1 (186 nm) and in the glass about 33 800 cm-1(295 nm), respectively. These emission and excitation spectra were contrasted to those of bulk sample crystals LaF3∶Pr3+.展开更多
文摘采用高温固相法合成了La_(2)MgTiO_(6)∶Mn^(4+)、La_(2)MgTiO_(6)∶Pr^(3+)、La_(2)MgTiO_(6)∶Pr^(3+),Mn^(4+)单掺杂和双掺杂荧光粉,并通过X射线衍射、扫描电镜、荧光光谱等测试方法对荧光粉的物相结构、形貌和发光特性进行了表征及分析。结果表明:成功合成了La_(2)MgTiO_(6)∶Mn^(4+)、La_(2)MgTiO_(6)∶Pr^(3+)、La_(2)MgTiO_(6)∶Pr^(3+),Mn^(4+)荧光粉且均为纯相;样品的粒径为1~2μm;La_(2)MgTiO_(6)∶Mn^(4+)在650~750 nm的红光发射是来自Mn^(4+)的2 E 1→4 A 2跃迁,La_(2)MgTiO_(6)∶Pr^(3+)在红光区域600~660 nm具有强烈的发射,归属为Pr^(3+)的3 P 0→3 H 6和3 P 0→3 F 2跃迁。当Mn^(4+)与Pr^(3+)共同掺杂于La_(2)MgTiO_(6)时,来自Mn^(4+)、Pr^(3+)不同波段的红光发射使荧光粉的发射光谱与植物光敏色素P r与P fr吸收光谱的重叠程度大幅增加,表明Mn^(4+)、Pr^(3+)共掺有效拓宽了La_(2)MgTiO_(6)荧光粉的红光发射区域,更符合植物照明的需求,在LED植物照明领域具有更明显的潜在应用价值。
文摘The vacuum ultraviolet (VUV) spectroscopic properties of praseodymium (Pr3+, 1at%) doped LaF3 nanocrystals/glass at room temperature and 20 K are reported. Two types of Pr3+ ions, those in LaF3 nanocrystals and those in the glass host, were excited to 4f 5d band by VUV using synchrotron radiation as an excitation source, and emissions of 1S0 → 1D2 (336 nm), 1S0 → 1I6 (397 nm ) of Pr3+ in the nanocrystals and emissions of 4f 5d → 3HJ, 3FJ of Pr3+ in the glass appeared at the same time. But unlike in the bulk sample crystals, emission of 3P0 → 3HJ, 3FJ as the second step of the quantum splitting (QS) of Pr3+ in the LaF3 nanocrystals was not observed at room temperature, which could be explained that Pr3+ ions in the glass absorbed the energy of 3P0 → 3H4 of Pr3+ in the nanocrystals. Two types of excitation spectra monitoring different emissions were also measured, so it could be observed that the lowest energy of 4f 5d band of Pr3+ in the nanocrystals was about 53 500 cm-1 (186 nm) and in the glass about 33 800 cm-1(295 nm), respectively. These emission and excitation spectra were contrasted to those of bulk sample crystals LaF3∶Pr3+.
