Sr3SiO5降温过程分解及对制备Sr3SiO5∶Eu^2＋的影响

Influences of Sr_3SiO_5 Decompose on the Cooling Process on the Preparation of Sr_3SiO_5∶Eu^(2+)

采用高温固相反应法制备Sr3SiO5∶Eu2+时,往往有Sr2SiO4∶Eu2+共存,从而影响Sr3SiO5∶Eu2+的发光性能。本文采用DSC/TG、淬冷法结合XRD,研究了Sr3SiO5∶Eu2+在降温过程中的分解反应。结果表明,Sr3SiO5是在1 250℃以上稳定存在的化合物,在降温过程中Sr3SiO5在1 250℃分解为Sr2SiO4和SrO。采用快速降温的方法可以抑制Sr3SiO5的分解。当降温速率小于10℃.min-1时,Sr3SiO5全部分解为Sr2SiO4和SrO;当降温速率为15℃.min-1时,样品主要物相为Sr3SiO5,但有少部分Sr3SiO5发生分解,当降温速率增大到20℃.min-1时,Sr3SiO5分解的量更少,即随着降温速率增大,Sr3SiO5分解的量减小,从而获得几近纯相的Sr3SiO5∶Eu2+荧光粉。

When Sr3SiO5∶Eu^2＋ was prepared by high temperature solid state method,Sr2SiO4∶Eu2＋ phase often coexists and affects the luminescent properties of Sr3SiO5∶Eu2＋.In the cooling process,the decompose reaction of Sr3SiO5∶Eu^2＋ were studied by DSC/TG,quenching method and XRD.Results indicate that the Sr3SiO5∶Eu^2＋ phase is a stable structure above 1 250 ℃.In the cooling process,the Sr3SiO5∶Eu^2＋ phosphor will be decomposed down into Sr2SiO4 and SrO at 1 250 ℃,and the decomposition of Sr3SiO5∶Eu^2＋ phosphor can be restrained by rapid cooling method.When the cooling rate less than 10 ℃·min^-1,all Sr3SiO5∶Eu2＋ decompose into Sr2SiO4 and SrO.When the cooling rate for 15 ℃·min^-1,the main object of samples is Sr3SiO5∶Eu^2＋,but there are still a few Sr3SiO5∶Eu2＋ decomposition.When the cooling rate is more than 20 ℃·min^-1,decomposition of Sr3SiO5∶Eu2＋ phase is less.Sr3SiO5∶Eu^2＋ decomposition reduced with increases of the cooling rate,and the pure Sr3SiO5∶Eu2＋ phosphor can be obtained.