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以KOH和Nb2O5为原料,采用水热法制备了KNbO3粉体。采用X射线衍射(XRD)、扫描电镜(SEM)、红外光谱(FTIR)研究了KOH浓度和反应温度的变化对制备粉体的相组成及形貌的影响。研究发现水热温度为220℃、KOH的浓度为10mol/L时,可以合成出X射线衍射纯KNbO3晶体,所制备的晶体发育完整,为片状晶体,晶体尺寸为0.5～1.5μm。当水热温度为180℃、KOH的浓度为10mol/L时,制备的X射线衍射纯KNbO3晶体发育也很完整,大部分仍为片状晶体,有少量晶体呈狭长形状,晶体尺寸为0.5～1μm。当水热温度为180℃、KOH的浓度为6mol/L时,制备的X射线衍射纯KNbO3晶体发育完整,KNbO3晶体为片状,晶体大小较均匀,晶体尺寸为0.4～1μm,有部分晶体聚集成棒状,长度约为10μm。FTIR光谱表明所制备的样品出现了Nb=O和Nb-O-Nb的振动峰,反应温度的变化并未使这两个振动峰的位置发生明显的变化。
Using KOH and Nb2O5 as raw materials, KNbO3 powder was prepared by hydrothermal method. The effects of KOH concentration and reaction temperature on the phase composition and morphology of the powders were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). It was found that X-ray diffraction pure KNbO3 crystal was synthesized when the hydrothermal temperature was 220 ℃ and the KOH concentration was 10mol / L. The prepared crystals were well developed as lamellar crystals with the size of 0.5-1.5μm. When the hydrothermal temperature is 180 ℃ and the KOH concentration is 10mol / L, the prepared pure KNbO3 crystals are also well developed, most of them are still lamellar crystals with a small amount of crystals with narrow shape and the crystal size of 0.5 ~ 1μm. When the hydrothermal temperature is 180 ℃ and the KOH concentration is 6mol / L, the prepared pure KNbO3 crystal grows well, the KNbO3 crystal is flaky, the crystal size is more uniform, the crystal size is 0.4 ~ 1μm, and some crystals gather Into a rod, the length of about 10μm. FTIR spectra showed that the vibrational peaks of Nb = O and Nb-O-Nb appeared in the prepared samples, and the change of reaction temperature did not change the positions of the two vibrational peaks obviously.