采用水热法,以KOH和Nb2O5为主要原料,分别加入KCl、K2SO4、K2CO3和KBr制备了铌酸钾(KNbO3)晶体。采用X射线衍射(XRD)、拉曼光谱、扫描电镜(SEM)、红外光谱(FTIR)、荧光光谱(PL)等方法研究了不同钾盐对合成的KNbO3晶体结构、微观形貌、产量及荧光性的影响。结果表明在水热合成过程中添加钾盐可以明显提高KNbO。晶体的产率,钾盐的种类对KNbO3的晶型和形貌有较大影响,当钾盐分别为KCl和KBr时,产物为0.5~1μm宽、1~10μm长,表面光滑的棒,分别为斜方六面体和正交晶型的KNbO3。当钾盐分别为K2CO3和K2SO4时,产物为不规则块状结构,分别为斜方六面体和正交晶型的KNbO3。FTIR分析表明样品在1383,1087,1050,879,614cm。处出现了Nb=0和Nb-O-Nb的振动峰。荧光光谱分析表明样品在396,450,467,481,491nm附近出现特征峰。
The potassium niobate (KNbO3) is prepared with niobium oxide (Nb2 05 ) and potassium hydroxide (KOH) as source material by hydrothermal method, which adds different kinds of potassium salt, for example, KCL, K2SO4, K2CO3, KBr. The influence of different potassiums on crystal texture, microstructure, output and fluorescence of the complex KNbO3 is studied by X-ray diffraction (XRD), Raman spectrum, scanning electron microscope (SEM), infrared spectroscopy (FTIR) and fluorescence spectra (PL). Results show that the productivity is improved greatly by the adding of potassium salt. The kind of potassium salt is a critical factor for the structure and morphological profile of the KNbO3. When the added potassium salt is KCI or KBr, the well crystallized KNbO3 rods whose structures are rhombohedral and ortho rhombic form respectively are formed with the width of 0.5 - 1 μm and the length of 1-10μm. Using K2CO3 or K2SO4 as the added potassium salt, the formed KNbO3 crystals whose structure are rhombohedral and ortho rhombic form respectively are irregular granular structures instead of rod-like structures. FTIR results indicate that the crystal show Nb;O and Nb--O--Nb vibration peaks at 1383, 1087, 1050, 879, 614 cm^-1. The fluorescence emissions of the KNbO3 samples are detected to appear the characteristic peaks at the wavelengths of 396, 450, 467,481, 491 nm.