碱金属离子,Gd^(3+),Ce^(3+)共掺杂的Lu_(3)Al_(5)O_(12)陶瓷粉体的光学性能

Alkali Metal Ion,Gd^(3+),Ce^(3+)Co-doped Lu_(3)Al_(5)O_(12) Optical Properties of Ceramic Powder

用高温固相法制备了(Gd_(x)M_(y)Lu_(0.99-x-y))_(3)Al_(5)O_(12):1%Ce^(3+)(x=0,0.01,0.25,0.5,0.75,y=0,0.005,0.01,0.02,0.05,0.1,M=Li^(+),Na^(+),K^(+),Cs^(+))系列陶瓷粉体。X射线衍射仪对合成粉末微结构进行表征,FLS920光谱仪测量样品的激发光谱、发射光谱和荧光寿命,CIE色度系统分析合成材料的色坐标。X射线衍射仪结果显示,不同浓度碱金属离子、Gd^(3+)、Ce^(3+)共掺杂Lu_(3)Al_(5)O_(12)样品仍为立方晶相,但随着碱金属离子、Gd^(3+)、Ce^(3+)掺杂浓度的增加,合成样品衍射峰稍有向小角度偏移。在350 nm激发下,与Lu_(2.97)Al_5O_(12):1%Ce^(3+)样品相比,共掺杂Gd^(3+)后的样品在511 nm附近发射强度降低且出现明显红移,随着Gd^(3+)浓度增加,Ce^(3+)能级寿命逐渐减小,范围为35~60 ns。与掺杂1%Ce^(3+),1%Gd^(3+)样品比较,分别共掺杂2%的Li^(+)、Na^(+)、K^(+)和1%的Cs^(+)后样品发光强度提高了5.1倍,2.93倍,1.79倍,1.28倍,同时样品中Ce^(3+)寿命继续减小。分别在λ=254.0 nm和λ=365.0 nm紫外灯照射下,随着Gd^(3+)掺杂浓度的增加,观察到合成样品从深黄绿色变化为暗红色,色坐标显示样品发光由黄绿光区逐渐移动到红光区域,且共掺杂碱金属离子后,粉体的发光更亮。

(Gd_(x)M_(y)Lu_(0.99-x-y))_(3)Al_(5)O_(12):1%Ce^(3+)(x=0,0.01,0.25,0.5,0.75,y=0,0.005,0.01,0.02,0.05,0.1,M=Li^(+),Na^(+),K^(+),Cs^(+))series ceramic powders were synthesized by high temperature solid phase method.The microstructure of the sample was characterized by XRD,the excitation spectrum,emission spectrum and fluorescence lifetime of the sample were measured by FLS920 spectrometer,and the color coordinate of the sample was analyzed by the CIE chromaticity system.XRD results show that the Lu_(3)Al_(5)O12 samples co-doped with different concentrations of alkali metal ions、Gd^(3+)and Ce^(3+)are still cubic crystal phases,but with the increase of alkali metal ions,Gd^(3+)and Ce^(3+)doping concentrations,the diffraction peaks of the samples shift slightly to a small angle.Under the excitation of 350 nm,compared with the Lu_(2.97)Al_(5)O_(12):1%Ce^(3+)sample,the emission intensity of the sample co-doped with Gd^(3+)at around511 nm decreased and appeared a significant red shift.With the increase of the doped Gd^(3+)concentration,the Ce^(3+)energy level lifetime gradually decreased.The range is 35~60 ns.Compared with the sample doped with 1%Ce^(3+)and 1%Gd^(3+),the luminescence intensity of the sample doped with 2%Li^(+),2%Na^(+),2%K^(+)and 1%Cs^(+)increased by 5.1 times and 2.93 times,respectively.At this time,the lifetime of Ce^(3+)in the sample continued to decrease.When the samples were irradiated under UV lamps withλ=254 nm andλ=365 nm,it was observed that with the increase of Gd^(3+)doping concentration,the color of the sample changed from dark yellow-green to dark red.The color coordinates show that the light-emitting area of the sample gradually moves from the yellow-green light area to the red light area.After co-doping with alkali metal ions,the sample emits brighter.