【摘要】 利用水热合成法在温度180～240℃和KOH浓度7～18mol/L的条件下合成了四方相KTa0.6Nb0.4O3(KTN)超微粉.通过XRD、UV-Vis和电导率等的测试分析,对粉体的水热合成工艺和性能进行了系统的研究.结果表明:KTN超微粉的相结构随着合成温度和矿化剂浓度的增加,从立方相过渡到四方相,且晶粒尺寸也随之增大.当KOH浓度增加时,KTN的禁带宽度Eg值由3.24eV增至3.34eV;当合成温度升高时,Eg值几乎没有变化.在KTN中掺杂金属W6+离子,可降低KTN陶瓷的电导率和漏电流,增大极化强度,使其易于极化,提高KTN材料的实用性.更多还原

【Abstract】 Tetragonal potassium tantalite niobate KTa0.6Nb0.4O3(KTN) ultra-fine powder had been synthesized via hydrothermal synthesis process at the temperature ranging from 180 ℃ to 240 ℃ and different KOH concentration(7—18 mol/L).The obtained particles were characterized by X-ray powder diffraction,UV-vis absorption spectrum and conductivity test.The hydrothermal synthesis processes of tetragonal KTN powder was systematically studied on the reaction temperature and KOH concentration.The research results showed that grain size increased and the structure of KTN particles transits from cubic phase to tetragonal phase with the increasing of reaction temperature and KOH concentration,respectively.The band gap Eg of KTN increased from 3.24 eV to 3.34 eV while KOH concentration was increased.Furthermore,the increase of temperature had almost no effect on the Eg.The conductivity and leakage current of KTN decreased while KTN was doped by W6+ metal ions,which made KTN easy to be polarized and be applied in practice.更多还原