engleski

Modified Aqueous Sol-Gel Route towards Complex Metal Oxides Containing Tungsten

Ferromagnetism and ferroelectricity are essential in numerous aspects of modern technology wherefore a need for synthesizing materials which have these properties appears. The main goal of this research is synthesis of complex perovskite nanoparticles with A2B2WO9 (A=earthalkali metal, B=transition metal) structure type by using specially modified sol- gel method reducing the time needed employing solid-state methods. Nanoparticles of Sr3Fe2WO9 and Ba3Fe2WO9 have been synthesized using modified Pechini route with citric acid solution at pH=5 (using concentrated ammonia solution), nitrate salts of strontium and barium and ammonium tungstate. Obtained powder has been calcined in a two-step process at different temperatures. These materials have been extensively studied using powder X-Ray Diffraction (PXRD), FT-IR spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy-dispersive X-ray diffraction spectroscopy (EDX). As obtained results have revealed that synthesize materials are 96 wt % pure and their average crystallite size has remained in nanometer range (15 nm to 27 nm) despite the high calcination temperatures.

citrate route ; ferroics ; perovskites ; sol-gel methods ; nanoparticles

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