K_2LaNb_5O_(15)粉体的熔盐法制备及其发光性能

Preparation and Luminescence Propety of K_2LaNb_5O_(15) Power by Moltn Salt Route

以氧化铌、氧化镧(La_2O_3)和氯化钾(KCl)为原料,采用熔盐法合成了K_2LaNb_5O_(15)粉体,用X射线衍射仪(XRD)和扫描电镜(SEM)对合成样品的结构和形貌进行了表征;并使用荧光光谱仪测试了K_2LaNb_5O_(15)粉体和掺Eu元素的K_2(La,Eu)Nb_5O_(15)粉体的激发-发射光谱.结果表明:在800℃时K_2LaNb_5O_(15)开始结晶,随着煅烧温度的升高,K2La Nb5O15粉体的形貌逐渐由棒状和颗粒状过渡为明显板条状.K_2LaNb_5O_(15)发光为405 nm的蓝光发射,是属于NbO_6引起的电荷跃迁型发光.对于K_2(La,Eu)Nb_5O_(15)粉体,发射光谱由基质自激活和Eu3+发射两部分组成.

Lanthanum potassium niobate oxide（ K2LaNb5O（15）） powder was successfully synthesized via molten salt method by using Nb2O5,La2O3 and KCl as the raw materials. The structure and morphology were characherized using X-ray diffraction and scanning electron microscope,and luminescence properties of the K2LaNb5O（15）and K2（ La,Eu） Nb5O（15） were tested. It is found that the K2LaNb5O（15）begin to crystallization without the formation of any intermediate phase at 800℃,and the crystals is flake shaped. The crystallinity is ascend with the calcination temperature increasing,and the crystals transforms into plate K2LaNb5O（15）powder.The main emission bands of the K2LaNb5O（15）is ascribed to MLCT of the distorted Nb O6 group center. For K2（ La,Eu） Nb5O（15） powder,emission spectrum is consisted of two parts,the substrate from activation and emission of Eu3 ＋.