助熔剂BaF_2在制备BaSi_2O_5∶Pb^(2+)过程中的机理  

Mechanism of Flux BaF_2 Used to Prepare BaSi_2O_5∶Pb^(2+)Phosphor

作　　者：唐永波[1] 杨庆华[1] 黄如喜[2] 朱宪忠[2] 王海波[2] 

机构地区：[1]南京工业大学材料科学与工程学院,江苏南京210009 [2]南京工业大学电光源材料研究所,江苏南京210015

出　　处：《发光学报》2006年第5期745-749,共5页Chinese Journal of Luminescence

摘　　要：采用高温固相合成法制备出BaSi2O5∶Pb2+荧光体。考察了BaF2的加入量对产物紫外发射强度的影响。用差示扫描量热分析,X射线衍射,光致发光光谱研究了掺入助熔剂BaF2后BaSi2O5∶Pb2+紫外发射强度显著增强的机理,并从热力学角度对实验结果作了分析。研究表明少量BaF2的掺入加快了反应速度;降低了BaSi2O5∶Pb2+形成温度,在高温下与SiO2反应生成SiF4气体,生成的SiF4再与BaCO3反应形成结晶良好的BaSi2O5∶Pb2+荧光体。The phosphor of BaSi2O5： Pb^2＋ has been widely used for manufacturing of black light lamps and treating many types of skin disease such as psoriasis, vitiligo, atopic dermatitis and so on. However, the detailed informations about the mechanism of flux BaF2 used for preparing BaSi2O5： Pb^2＋ phosphor can not be found in literature. The aim of this research is to work out the mechanism of flux BaF2 in the process of preparing BaSi2O5： Pb^2＋Ba Si2O5： Pb^2＋ sample was prepared by solid state reaction method at high temperature. Mixing compounds of barium and silicon which upon heating will react to form barium disilicate with a activating proportion Pb（ NO3 ）2. The firing temperature is approximately 1 100℃. Crystal structure of BaSi2O5： Pb^2＋. phosphor is β-BaSi2O5. Ba2. was substituted by Pb^2＋ partly in BaSi2O5 lattice so the XRD pattern of BaSi2O5： Pb^2＋ phosphor is identical with BaSi2O5 crystal. Effect of BaF2 concentration on ultraviolet intensity was studied. Mechanism that the addition of flux BaF2 promotes the solid reaction and enhances BaSi2O5： Pb^2＋. ultraviolet emission intensity was investigated by X-ray diffraction, heat-flux differential scanning calorimetry, and photoluminescence. Results indicate that BaSi2O5： Pb^2＋ phosphor forms at 800 ℃ by adding BaF2. High temperature firing with a small amount of BaF2 results in a phosphor with high emission intensity, BaSi2O5： Pb^2＋ emission intensity reach its maximum when the amounts of flux BaF2 is 8%. BaF2 and SiO2 combine to form SiF4 and BaSi2O5 then the formed SiF4 will react with BaCO3 to form BaSi2O5 again. The addition of flux BaF2 promote the solid state reaction, the temperature forming BaSi2O5： Pb^2＋. phosphor was reduced to 800℃ and it is consistent with thermodynamics theory.

关 键 词：重硅酸钡 助熔剂 机理 热力学分析 

分 类 号：O482.31[理学—固体物理]