摘要
采用高温固相反应法合成了BaMgAl10 O17∶R(R =Eu ,Mn)荧光体 ,测量了荧光体的真空紫外激发光谱和相应的发射光谱 ,观察到基质吸收带位于 16 5nm附近 ,Mn2 + 离子的吸收位于 170～ 2 40nm范围 ,Eu2 + 离子的 4f→ 5d吸收位于 2 10～ 40 0nm范围。真空紫外光谱特性的研究表明基质与激活离子之间存在较好的能量传递。
In recent years, vacuum ultraviolet (VUV) optical properties have become of special importance for luminescent materials. The main interest has been in the development of new and efficient plasma phosphors to realize a gas discharge color picture display panel and mercury-free fluorescent lamps. Plasma phosphors are required to have high conversion efficiency under VUV excitation. Therefore, the strong absorption of phosphors in the VUV region is very important for the plasma phosphor. While compounds with aluminate groups have strong absorption in the VUV region. Thus VUV excitation spectra of BaMgAl 10O 17∶R 2+ (R=Eu,Mn) were investigated. The starting materials were Al 2O 3 (4N), MgO(A.R.), BaCO 3(4N), En 2O 3 (4N) and MnCO 3(A.R.). They were thoroughly mixed in an agate mortar with a certain AlF 3 as flux. The mixtures were introduced in an alumina crucible and heated for 2 hours at 1 450℃ in the presence of carbon. The VUV excitation spectra of the visible luminescence of BaMgAl 10O 17∶Eu 2+ is composed of two broad bands peaking at about 165 and 248nm. One band in the region from 200nm to 300nm is attributed to the absorption of the 4f→5d transition of Eu 2+ ions. The other band in the region from 120nm to 200nm is due to the host absorption. This result indicates that there is an energy transfer from host to Eu 2+ ions. Under 147nm excitation, the emission spectrum of Ba 0.9Eu 0.1MgAl 10O 17 consists of a broad band at about 448nm, corresponding to the 4f→5d transition of Eu 2+ ions. The VUV excitation spectrum of BaMg 0.8Mn 0.2Al 10O 17 consists of three broad bands in the range from 120nm to 240nm. The two bands located in the range from 120nm to 180nm are ascribed to the absorption of the host absorption. The band peaking at about 198nm is not attribute to the host absorption, it may be associated with the absorption of Mn 2+. For a free ion of Mn 2+,the energy separation between 6S(3d 5) and 6D(3d 44s) levels had known to be around 6.3×10 4cm -1. Therefore, it may be assigned to one of these 3d 5→3d 44s transitions. Under 147nm excitation, the emission spectrum is dominated by the green Mn 2+-band at about 516nm. It is assigned to the transition from the lowest excited state to the ground state, i.e., 4T 1( 4G)→ 6A 1( 6S). The green emission of Mn 2+ indicates that Mn 2+ ions occupy the sites of Al 3+ which have tetrahedral coordination.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2003年第1期87-90,共4页
Chinese Journal of Luminescence
基金
国家自然科学基金资助项目 ( 2 0 0 710 31)
