Abstract

ANACONA, Oscar R; GARCIA, Ducinei; KIMINAMI, Ruth H.G.A  and  RAIGOZA, Claudia F.V. Effect of temperature on the crystalline structure of K_0.5Na_0.5NbO₃ ceramics powder obtained by combustion reaction synthesis. Rev. LatinAm. Metal. Mater. [online]. 2013, vol.33, n.1, pp.108-115. ISSN 0255-6952.

This paper discusses how temperature influences the obtention of single-phase K_0.5Na_0.5NbO₃ (KNN) nanometric ceramic powders, synthesized by the combustion method. K₂CO₃, Na₂CO₃, and NH₄[NbO(C₂O₄)₂(H₂O)] . H₂O were used as cation sources and a mixture of urea / glycine in relation 50/50 was used as fuel. The solution containing precursors and fuel was placed in a preheated muffle furnace, where the combustion took place. In this process, the effect of four different temperatures (500, 600, 700 and 800°C) was analyzed. The phases present in the ceramic powders, the microstructure and the morphology were determined by X-ray diffraction (XRD), Fourier transform infrared (FTIR) Spectroscopy, and scanning electron microscopy (SEM). Experimental results show that pure perovskite phase was formed at temperatures as low as 500°C. Furthermore, the obtained powder has monoclinic symmetry and average particle size of ~ 27 nm. We conclude that the homogeneity of the precursor solution and a low processing temperature play a key role in the formation of nano-particles of KNN.

Keywords : synthesis; combustion; KNN; X-ray diffraction; microstructure.

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