CAJ | 학술논문

采用CaCl_2作助熔剂同时又作反应物,利用固相法在碳还原气氛下合成了Ca_2MgSi_2O_7:Eu~(2+)发光粉,确定其最佳的合成条件为按CaCO_3、Mg(OH)_2、SiO_2、CaCl_2的量的比1.5:1:2:2.4称取原料,烧结温度为900 ℃,烧结时间为3 h.合成的样品可被360～480 nm的光有效激发,得到发射峰值位于529 nm的绿光.该发光粉Eu~(2+)的最佳掺杂摩尔分数为0.02.与高温法相比,低温法制备的Ca_2MgSi_2O_7:Eu~(2+)发光粉激发光谱形状表现出一些差别,并且发射光强度显著增强,低温制备的Ca_2MgSi_2O_7:0.02Eu~(2+)的发射强度是高温制备样品的261%.
채용CaCl_2작조용제동시우작반응물,이용고상법재탄환원기분하합성료Ca_2MgSi_2O_7:Eu~(2+)발광분,학정기최가적합성조건위안CaCO_3、Mg(OH)_2、SiO_2、CaCl_2적량적비1.5:1:2:2.4칭취원료,소결온도위900 ℃,소결시간위3 h.합성적양품가피360～480 nm적광유효격발,득도발사봉치위우529 nm적록광.해발광분Eu~(2+)적최가참잡마이분수위0.02.여고온법상비,저온법제비적Ca_2MgSi_2O_7:Eu~(2+)발광분격발광보형상표현출일사차별,병차발사광강도현저증강,저온제비적Ca_2MgSi_2O_7:0.02Eu~(2+)적발사강도시고온제비양품적261%.
Alkaline earth silicate Ca_2MgSi_2O_7:Eu~(2+) phosphors were prepared under a reducing atmosphere by solid-state reaction using CaCl_2 as flux medium and starting materials. Samples sintered under different CaCO_3 concentration, different temperatures and different time were obtained. The effect of these conditions on the structure was studied by X-ray diffraction (XRD). The synthetic conditions were optimized at the molar ratio of starting materials CaCO_3:Mg(OH)_2:SiO_2:CaCl_2 equal to 1.5:1:2:2.4, sintering temperature 900 ℃ and sintering time 3 h. The photoluminescence (PL) spectra of the as-prepared phosphor powders were measured. The results indicated that the Ca_2MgSi_2O_7:Eu~(2+) phosphor can be effectively excited by the light in the wavelength range of 360～480 nm and emission spectrum shows a broad green emission band centered at 529 nm with a bright green emission. And it is possible to determine the distribution of this broad emission band in the spectrum associated with transition from the 4f5d level of Eu~(2+) ion which only replaces the Ca~(2+) ion site with a coordinate number of eight. Furthermore, the broad green emission band is asymmetric as a result of the re-absorption of the blue light by the green-emission light. The Ca_2MgSi_2O_7:Eu~(2+) phosphors were also synthesized at 1 200 ℃ for 4 h in a reducing atmosphere using H_3BO_3 as flux medium and CaCO_3,Mg(OH)_2,SiO_2 as starting materials. Comparing the high temperature and low temperature methods, we found that their exitaton spectrum profiles are different, and the emission intensity of Ca_2MgSi_2O_7:xEu~(2+) (x=0.01, 0.02, 0.03, 0.04, 0.07) phosphor prepared at 900 ℃ is higher than that of powders prepared at 1 200 ℃.