LaAlO3∶Eu3+的绿色化学合成及光谱性质

Green Chemical Synthesis and Luminescence Properties of LaAlO_3 Eu^(3+)

提出一种合成LaAlO3的新方法,该方法操作简单、成本低、无污染。将化学计量比的反应物La(OH)3/La2O3和Al(OH)3放入反应釜中,于220℃温度下水热活化处理,快速加热至900℃反应即可得到LaAlO3。XRD结果表明,所合成的LaAlO3为三方晶系。PL结果表明,所合成的LaAlO3∶Eu3+的主要发射为Eu3+的5D0→7F1磁偶极跃迁发射和5D0→7F2电偶极跃迁发射,红橙比随着Eu3+离子掺杂量的增加而变大。在VUV-UV激发光谱中,LaAlO3∶Eu3+位于VUV光谱区的基质吸收很弱,而位于~315 nm的O2--Eu3+的电荷迁移跃迁带(CT)则较强。

A facile,environmentally friendly,low cost method was employed to synthesize perovskite-type LaAlO 3 powders.The stoichiometric mixtures of La( OH) 3 / La 2 O 3,and Al( OH) 3 were activated by a hydrothermal treatment in teflon-lined stainless steel autoclave at 220 ℃ for 3 d,and then the precursors were quickly heated to 900 ℃ and reacted for 5 h to obtain LaAlO 3.The obtained samples were characterized by X-ray diffraction( XRD) and photoluminescence( PL) spectra.XRD result shows that LaAlO 3 crystal structure belongs to the rhombohedral system with the space group of R 3c( No.167).PL results indicate the main emissions of LaAlO 3 ∶ Eu3 +come from the magnetic dipole-dipole5D 0 →7F 1 transition and the electric dipole-dipole5D 0 →7F 2 transition.The ratio value of the intensity of Eu3 +:5D 0 →7F 2 transition to the intensity of Eu3 +:5D 0 →7F 1 transition increases with the increase of Eu3 +concentration.Host absorption of LaAlO 3 ∶ Eu3 +in the VUV range is weaker than that of O2--Eu3 +charge transfer band in the UV range.