鈮酸鉀 (KNbO3) 為一擁有良好電學特性之鈣鈦礦結構材料，過去對於鈮酸鉀相關的研究多著墨於其光學特性的應用上，近來由於其良好的壓電特性使得鈮酸鉀成為無鉛壓電材料開發的熱門人選之一。如同其他鈣鈦礦結構的鐵電材料，鈮酸鉀的許多物理性質預期會深受添加物的影響，故此次研究採結晶化學法選取前人未使用過的添加物，以 V5+ 作為取代物，研究取代後鈮酸鉀於燒結及電學特性的改變。本實驗採用一般的固相反應合成方法獲得 K(Nb1-xVx)O3 粉末。由實驗結果得知，添加 V5+ 後，出現 K(Nb1-xVx)O3 結晶相的溫度由 550℃ 提前至 500℃ ，而 800℃ 持溫 24 h 所得之 K(Nb1-xVx)O3 系統煆燒粉末的結晶溶解度小於 5 mole%，且於 V5+ 添加後之相轉換溫度及居禮溫度皆有上升的現象。進行燒結實驗時，各成分之最佳燒結體密度均在 93% 以上，而高溫與較長時間的持溫會使得晶粒發生異常成長的現象，並產生微裂縫使得密度無法提昇。於電性量測方面，添加後電阻係數明顯下降，而相對介電常數於 1 kHz 時因為空間電荷影響而有上升的現象，但於 1 MHz 量測之介電常數則下降。鐵電滯迴曲線及壓電性質量測時，因添加後導電度上升，故僅 KNbO3 有量測數據，其 Pr 值及 Ec 值分別為 0.36 mC/cm2 與 353.6 kV/cm，而 kp 與 kt 值分別為 23.8% 與 23.4%。

　　Potassium Niobate (KNbO3), a ferroelectric material with good electric properties, is of interest for researches in optical applications. Recently it has been reported that KNbO3 single crystal have large piezoelectric constants, and this make it to be one of the most promising candidates for lead-free piezoelectric applications. Like many other oxide ferroelectrics with the perovskite-type structure, physical characteristics of KNbO3 are expected to be influenced by doping. In this research, we study the effect on sintering behavior and dielectric properties after vanadium doped. The powder is prepared by conventional solid-state reaction. Experimental results show that synthesis temperature of K(Nb1-xVx)O3 could be lowered after V5+ doped, and the crystalline solubility of the system is smaller than 5 mole%, both of phase transition temperature and Curie temperature increase after doping. Relative density of K(Nb1-xVx)O3 ceramics could reach 93%, and would decrease because of abnormal grain growth after sintering at higher temperature for long soaking time. DC resistivity and dielectric constant at 1MHz are lower after doping, but become higher at 1 kHz because of space charge effect. Measurement data of Pr, Ec, kp, and kt of KNbO3 are 0.36 mC/cm2, 353.6 kV/cm, 23.8%, and 23.4%, respectively.

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