【摘要】 用固相反应法合成了铽激活的磷酸钇钆体系的试样,测定了在阴极射线、紫外线和X射线激发下,体系基质组成和激活剂含量的改变对其发光性质的影响,讨论了Tb³⁺浓度猝灭的机理。更多还原

【Abstract】 Terbium activated simple phosphates of lanthanum, yttrium, and gadolinium are cathodo-,UV photo-,and roentgeno-luminophors.As regard to the double phosphates there was only one article written by D’Silva relating to the study of roentgenoluminescent properties of the system yttrium gadolinium phosphate.In this work samples of terbium activated yttrium gadolinium phosphate system Y1-xGdxPO4:Tb were prepared by solids state reaction of corresponding metal oxides and ammonium hydrophosphate in the presence of flux sodium pyrophosphate.Their luminescent properties under the excitation of cathode rays,UV light,and X-rays have been investigated. A possible mechanism of concentration quenching of activator terbium ions has been postulated.Figures 1-1,1-2, and 1-3 show the cathode-,UV photo-,and roentgeno-luminescence spectra.They all consist of a set of sharp emission lines corresponding to the 5D3-7EJ and 5D4-7FJ transitions of terbium.In 5D3-7FJ transitions the 5D3-7F6( = 382 nm)is the strongest one.In 5D4-7FJ transitions the 5D4-7F5( = 544 nm) is the strongest one.Figures 2-1,2-2,and 2-3 show that two strongest transitions 5D3-7F6 and 5D4-7F5 under CR-,UV-,and X-ray excitation reach maximum as gadolinium content equals to 0.25 mole per cent.Measurements also show that the brightness of CR-,UV- and roentgeno-Iuminescence of Y1-xGdxPO4 :Tb comes up to a maximum as x= 0.25. Brightness of Y0.75Gd0.25PO4:Tb is twice as high as that of YPO4:Tb.Dependence of the relative intensities of 5D3-7F8 and 5D4-7F5 transitions on the terbium concentration exhibit in a similar manner in all the three excitation cases,as shown in the I-lgCTb3 +] plots, Figures 4-1,4-2,and 4-3. As Tb3 + concentration reaches above a certain value,the concentration quenching occures,which may be ascribed to the dipole-dipole interaction in the case of 5D3-7FJ transitions and to the interaction between neighboring activator Tb3 + ions in the case of 5D4-7FJ transitions.更多还原