共沉淀法合成小粒径PDP绿粉中的物相转变和颗粒生长过程研究

Research on the phase transition and the particle growth of the green phosphor for PDP synthesized by the co-precipitation method

使用化学共沉淀法合成出粒径为1～2μm的Mg掺杂的PDP用铝酸盐绿色荧光粉,研究了共沉淀产物在高温煅烧中的物相变化和颗粒长大过程,并使用该超细PDP绿粉进行了涂屏实验。结果表明,共沉淀产物的物相转变过程异常复杂,中间相包括Ba-CO3、γ-Al2O3、BaF2、BaAl2O4和两个含Mn的化合物,在整个物相转变过程中没有出现α-Al2O3相;合成温度比高温固相反应法明显降低,1200℃时即可形成物相纯净的Mg掺杂的BaAl12O19∶Mn2+荧光粉。该方法有效地控制了荧光粉的颗粒大小和形貌,制备出的荧光粉颗粒呈六角片状,粒径细小,且具有优良的发光特性。喷涂实验表明,使用该荧光粉得到荧光粉层致密、表面平坦,有利于获得更大的放电空间。

Mg doped BaAl12O19∶Mn2＋ green ph osphor for PDP with the particle size of 1-2μm was synthesized by the chemical co-precipitation method,the phase transition and particle growth process of t he phosphor during the baking process were investigated,and the screen coating experiment was made by spraying the phosphor.The results show that,the phase t ransition is extremely complicated,the transition phases include BaCO3,γ-A l2O3,BaF2,BaAl2O4 and two phases contain Mn,no α-Al2O3 phase appears during the entire process;the formation temperature of BaAl12O 19 phase by the co-precipitation method is approximately 1200℃,which is s ignificantly lower than that by the high temperature solid state reaction method.A well dispersed Mg doped BaAl12O19∶Mn2＋ green phosphor wit h small particle size and hexagonal flaky shape can be prepared by this method. The result of the screen coating experiment showed that,the phosphor layer spra yed with the phosphor is dense and with a flat surface,which is beneficial to o btain a larger discharge space.