棒状KNb_3O_8晶体的熔盐法制备及荧光性的研究

Preparation and Fluorescence Properties of Rod Potassium Triniobate Crystals

以KCl、K2SO4和Nb2O5为原料采用熔盐法合成了铌酸钾晶体,研究了反应温度和反应时间对粉体结构和形貌的影响。反应温度为700℃,反应还没有开始。温度升到800℃,反应2h,有少量棒状和一些大的块状KNb3O8出现。反应温度升到900℃,反应1h时,产物中出现大量的棒状结构的KNb3O8晶体。反应2和3h时,棒状结构的宽度为200～300nm,长度为几μm。反应时间为4h时,棒宽增加到500nm左右,最大长度为几十μm,表面比较光滑。

Potassium niobate crystals had been synthesized by a molten salt process with KCl,K2SO4 and Nb2O5 as materials.The effect of reactive temperature and reactive time on the structure and morphology of the powders were discussed,and the optical properties of the samples were studied.The reactive process had not begun when the reactive temperature was 700℃.A small amount of rod and some bulk KNb3O8 crystals were formed,when the sample was treated at 800℃ for 2 hours.A large amount of rod KNb3O8 crystals were formed,when the sample was treated at 900℃ for 1 hour.When the reactive time increased to 2 and 3 hours,the width of the nanorods was 200～300nm and their length was several microns.Their width was around 500nm,their maximum length was tens of microns and their surface was smooth when the reactive time increased to 4 hours.Fluorescence spectra showed that two fluorescence peaks appeared at near 250.0nm and 500.5nm when the reactive temperature of the samples was 900℃,and the KNb3O8 crystals had fluorescence.