We have designed a new synthesis method for the ternary metal hydride Mg(2)FeH(6) based on the direct reaction of simple hydrides under high-pressure conditions. Well-crystallized samples were prepared in a piston-cylinder hydrostatic press at 2 GPa and temperatures around 750 degrees C from mixtures of MgH(2) and Fe enclosed in gold or platinum capsules. Seven different samples have been prepared under different conditions. X-ray powder diffraction analysis was used to identify and assess the purity of the samples, through Rietveld analyses of the crystal structure (K(2)PtCl(6)-type). Mg(2)FeH(6) shows a cubic symmetry with space group Fm-3m. SEM images show an average particle size of 1-2 mu m for Mg(2)FeH(6); the microcrystals present well-grown faces and display a high homogeneity of shapes and sizes. Thermogravimetric analysis has been carried out to determine not only the hydrogen desorption temperature but also the hydrogen contents. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.