Thermodynamic evaluation and hydrothermal preparation of KxNa1-xNbO3
来源期刊:Rare Metals2008年第4期
论文作者:ZHANG Ci a, LV Haijun a, GUO Min a, ZHANG Mei a, and WANG Xidong b a Department of Physical Chemistry, University of Science and Technology Beijing, Beijing , China b College of Engineering, Peking University, Beijing , China
文章页码:371 - 377
摘 要:The Gibbs free energies of reaction △ r GTof KNbO3 and NaNbO3 were calculated and then that of KxNa1-xNbO3 was estimated. On the ba-sis of the thermodynamic calculation results, the hydrothermal temperatures were designed at 100, 160, and 230°C respectively. However, NaNbO3 was prepared when the heating temperature was higher than 160°C, and KNbO3 and KxNa1-xNbO3 were obtained at 230°C, sug-gesting that only at a higher temperature the kinetic requirement is satisfied. According to the X-ray diffraction results, both the solid solu-tions, NaNbO3-based solid solution, Na1-xKxNbO3, and KNbO3-based solid solution, K1-xNaxNbO3, were hydrothermally synthesized in 6 mol/L alkali (NaOH and KOH) solution at 230°C.
摘要:The Gibbs free energies of reaction △ r GTof KNbO3 and NaNbO3 were calculated and then that of KxNa1-xNbO3 was estimated. On the ba-sis of the thermodynamic calculation results, the hydrothermal temperatures were designed at 100, 160, and 230°C respectively. However, NaNbO3 was prepared when the heating temperature was higher than 160°C, and KNbO3 and KxNa1-xNbO3 were obtained at 230°C, sug-gesting that only at a higher temperature the kinetic requirement is satisfied. According to the X-ray diffraction results, both the solid solu-tions, NaNbO3-based solid solution, Na1-xKxNbO3, and KNbO3-based solid solution, K1-xNaxNbO3, were hydrothermally synthesized in 6 mol/L alkali (NaOH and KOH) solution at 230°C.
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