助熔剂对BAM∶Eu2+荧光粉合成机理和发光强度的影响

采用高温固相法制备了BaMgAl10O17∶Eu2+(BAM∶Eu2+)蓝色荧光粉,采用X射线衍射、扫描电子显微镜和荧光光谱等手段,考察了不同助熔剂以及反应对BAM∶Eu2+晶体结晶度、物相纯度、粉体颗粒形貌和发光强度的影响,并对合成反应的机理进行了分析。结果表明,采用不同的助熔剂,均能制备出BAM∶Eu2+发光材料,Eu2+的掺入对基质晶体结构没有明显的影响;相对不加助熔剂时,烧结温度大幅度降低,且制备的样品形貌更规整、颗粒大小更趋均一;随着烧结时间的延长,样品结晶更趋完整、杂相减少,粉体发光强度随之提高;随助熔剂用量的增加,粉体的发光性能得到改善,但助熔剂用量过量时,粉体结块、团聚,粉体的发光性能变差;采用不同的助熔剂,合成反应的机理发生变化,所得样品的结晶完整性、杂相组成和含量、发光中心的分布、粉体料径等性能产生相应变化,最终导致样品的发光性能发生改变,样品的特征发射峰强度随AlF3、H3BO3、MgF2、Li2CO3、无助熔剂依次降低。

Effects of Fluxes on Synthesis Mechanism and Emission Intensity of BaMgAl10O17∶ Eu2+

BaMgAl10O17:Eu2+ phosphors were synthesized by high temperature solid-state reaction method.Using the X-ray powder diffraction,scanning electron microscopy and photoluminescence spectra,the effects of different fluxes and reaction time on such properties as crystals crystallinity,phase purity,particle morphology and luminescence intensity of the blue phosphor were investigated.The mechanism of synthesis of BaMgAl10O17:Eu2+ with different fluxes was analyzed.The results show that BaMgAl10O17:Eu2+ phosphors with more regular morphology,uniform particle size and crystals crystallinity can be obtained at low sintering temperature,comparing with non-flux reaction condition.Incorporation of Eu2+ has less influence on crystal structure of BaMgAl10O17 matrix.Along with the agglutination time’s extension,the sample’s crystallization becomes more completely,the content of impurity phase in it reduces and its luminous intensity increases.As different fluxes are used,the mechanism of synthesis of BaMgAl10O17:Eu2+ will change.The performances of prepared sample such as crystallization integrity,phase purity and the luminescent center distribution have corresponding change with the change of the synthesis mechanism,thus the luminescent properties of the samples change correspondingly.