柠檬酸螯合法制备BaHfO3:Ce3+纳米材料及其发光特性

Preparation and Luminescence Characteristics of Nano BaHfO3:Ce3+ Powders Prepared by Citric Acid Chelating Process

摘要:

通过柠檬酸螯合法合成BaHfO3:Ce3+纳米粉体。采用TG-DTA、XRD、SEM等手段对粉体进行了表征，用荧光光度仪分析样品的激发光谱和发射光谱。结果表明：在CA:EG=1:3的条件下得到干凝胶前驱体，经1050 ℃煅烧2 h，合成出结晶度高、近似球形、粒径尺寸约为40 nm的BaHfO3:Ce3+纳米粉体。Ce3+掺杂浓度为0.9 mol%的BaHfO3:Ce3+样品激发光谱和发射光谱的相对强度最大。激发光谱有两个较宽的谱带，发光峰值分别在393和445 nm波长处最大。样品在393和445 nm的

Abstract:

Citric acid chelating method was used to prepare Ce3+ doped BaHfO3 nano-powder. TG-DTA, XRD and SEM were employed to characterize the powder. The excitation and emission spectra of the specimens were analyzed by the fluorescence photometer. Results show that BaHfO3:Ce3+ nanometer powder with high degree of crystallinity, nearly spherical morphology and 40 nm particle size could be synthesized after the precursor gel prepared under the condition of CA:EG=1:3 was calcined at 1050 ℃ for 2 h. The maximum relative intensities of the excitation spectra and emission spectra appeared for the BaHfO3:Ce3+ specimen with Ce3+ doped concentration of 0.9 mol%. The excitation spectrum has two relatively wide spectrum bands where there are maximum peak values at the wavelength of 393 nm and 445 nm, respectively. The emission spectra at lex= 393 nm and lex=445 nm also have two spectrum bands where exist maximum peak values at 530 nm and 590 nm, respectively, corresponding to 5d→2F5/2 and 5d→2F7/2 transitions of Ce3+ cation, respectively. The emission spectra at 393 nm and 445 nm are obviously different, because the 4f ground State of Ce3+ cation is formed by two energy levels, with the energy difference of about 2000 cm-1.