Eu^(2+)激活的(CaMgBa)_5(PO_4)_3(ClF)荧光体发光性能的研究

The Luminescence of Eu^(2+)-Activated (CaMgBa)_5(PO_4)_3(ClF) Phosphors

Ca_5(PO_4)_3Cl:Eu^(2+)和Ba_5(PO_4)_3Cl:Eu^(2+)都具有较强的蓝色荧光,它们的发射峰峰值波长分别为460nm和443nm,半高宽均为40nm。(Ca_(1-x)Ba_x)_5(PO_4)_3Cl:Eu^(2+)二元体系的固溶体范围为x=0.0～0.4和0.6～1.0,其中(Ba_(0.8)Ca_(0.2))_5(PO_4)_3Cl:Eu^(2+)发光亮度最高,发射峰峰值波长为508nm,半高宽为95nm,发光颜色为蓝绿色。Mg部分取代(Ba_(0.8)Ca_(0.2))_5(PO_4)_3Cl:Eu^(2+)中阳离子后,其发光强度可提高约25％。

This paper discusses the luminescent properties of Eu2+ ions in alkaline earth ha-lophosphates crystals. Samples were prepared by solid state reactions.The spectra of emission and excitation were determined. Their emissions arise from the 4f65d→8S7/2 transitions of Eu2+ ions. The peak wavelengths of the emission hands of Ca5(PO4)3Cl:Eu2+, Ba5(PO4),Cl:Eu2+ and (Ca0.2Ba0.8)5(PO4)3CI:Eu2+ are 460nm, 443nm and 508nm respectively. Their excitation spectra are wide band. They shows that these phosphors can absorb 240-400nm UV light effectively.By means of X-ray diffraction, the lattice parameters of samples (Ca1-xBax)5 (PO4)3Cl:Eu2+ have been obtained and the subsolidus phase relationships in this system could be determined from the variation of the lattice parameters vs. compositions. The results indicated that this system forms solid solutions in the range of 0.0<x<0.4 and 0.6<x<1.0.The variation of luminescence with samples' composition in the system (Ga1-xBax)5 (PO4)3Cl:Eu2+ were studied. The sample of (Ca0.2Ba0.8)5(PO4)3CI :Eu2+ shows a maximum bluish green emission with a peak wavelength of 508nm and a bandwidth of 95nm.It has also been confirmed that when Ba is replaced by about 0.45-0.75 Mg mole/ mole host in (Ca0.2Ba0.8)5(PO4)3 Cl :Eu2+ ,the luminescent brilliance increases about 25%.