Preparation of Morphology‐Controlled Plate‐Like Sodium Niobate Particles by Hydrothermal Synthesis

Sodium niobate (NaNbO3) particles with plate-like morphology and hexagonal unit cells were prepared by the hydrothermal method. The result of SEM showed that the hexagonal NaNbO3 were characterized by plate-like morphology with a diameter of 5–15 μm and a thickness of 1–2 μm. The crucial influences on the morphology and crystal phase of the NaNbO3, such as concentration of [OH−], surfactant, and K+:Na+ ratio, were established. By further calcination treatment, the plate-like hexagonal NaNbO3 particles could be completely transformed into perovskite structure without morphology change. The XRD and EBSD results indicate that the major face of the calcined particles is parallel to the crystallographic (001)pc (pseudo cubic index) plane. Compared with the traditional high-temperature molten salt method, this work provides a simpler way to prepare the template for fabricating textured ceramics.

[1]  T. Karaki,et al.  Morphotropic Phase Boundary Slope of (K,Na,Li)NbO3–BaZrO3 Binary System Adjusted Using Third Component (Bi,Na)TiO3 Additive , 2013 .

[2]  S. Bai,et al.  Two-step Synthesis of Platelike Potassium Sodium Niobate Template Particles by Hydrothermal Method , 2013 .

[3]  Kongjun Zhu,et al.  Hydrothermal synthesis of sodium niobate with controllable shape and structure , 2012 .

[4]  D. Xue,et al.  Crystallization of NaNbO3 microcubes by a solution-phase ion exchange route , 2011 .

[5]  Hanxing Liu,et al.  Structure Control of NaNbO3 Template for Textured Ceramics Synthesized by Two-Step Molten Salt Method , 2010 .

[6]  Wei Zhang,et al.  Formation mechanism of NaNbO3 powders during hydrothermal synthesis , 2010 .

[7]  R. Meyer,et al.  Mechanistic Interpretation of the Aurivillius to Perovskite Topochemical Microcrystal Conversion Process , 2010 .

[8]  M. Kosec,et al.  Crystal structure and phase transitions of sodium potassium niobate perovskites , 2009 .

[9]  Tiedong Sun,et al.  Hydrothermal Synthesis of (K,Na)NbO3 Particles , 2008 .

[10]  H. Takao,et al.  Synthesis of polycrystalline platelike NaNbO3 particles by the topochemical micro-crystal conversion from K4Nb6O17 and fabrication of grain-oriented (K0.5Na0.5)NbO3 ceramics , 2007 .

[11]  Jingfeng Li,et al.  Normal Sintering of (K,Na)NbO3‐Based Ceramics: Influence of Sintering Temperature on Densification, Microstructure, and Electrical Properties , 2006 .

[12]  Xueping Gao,et al.  Structural evolution in a hydrothermal reaction between Nb2O5 and NaOH solution: from Nb2O5 grains to microporous Na2Nb2O6.2/3H2O fibers and NaNbO3 cubes. , 2006, Journal of the American Chemical Society.

[13]  M. Kosec,et al.  Electro-optic properties of KNN–STO lead-free ceramics , 2005 .

[14]  Yiping Guo,et al.  (Na0.5K0.5)NbO3–LiTaO3 lead-free piezoelectric ceramics , 2005 .

[15]  Eric Cross,et al.  Materials science: Lead-free at last , 2004, nature.

[16]  Yasuyoshi Saito,et al.  Lead-free piezoceramics , 2004, Nature.

[17]  A. Dias,et al.  Electroceramic Materials of Tailored Phase and Morphology by Hydrothermal Technology , 2003 .

[18]  S. Haile,et al.  Hydrothermal synthesis of KNbO_3 and NaNbO_3 powders , 2003 .

[19]  S. Chu,et al.  Properties of (Na, K)NbO 3 and (Li, Na, K)NbO 3 Ceramic Mixed Systems , 2003 .

[20]  Chung‐Hsin Lu,et al.  Hydrothermal synthesis of nonlinear optical potassium niobate ceramic powder , 1998 .

[21]  N. Kinomura,et al.  A new allotropic form with ilmenite-type structure of NaNbO3 , 1984 .