Iron phosphorus trisulfide FePS(3) is related to the chalcogenides. It is characterized by layered structure. FePS(3) powder was prepared by solid state reaction and heated up to 650 degrees C using two different heating rates 1 degrees C/min and 40 degrees C/min. The results showed that the FePS3 produced with slow heating rate was highly ordered single crystalline phase while the powder produced with the fast heating rate was poly crystalline phase. The surface morphology and the grain size were influenced by the heating rate used for preparation. The thermal resistance of the highly ordered crystalline phase extended till 680 degrees C while the less ordered one extended to 660 degrees C. The products at 900 degrees C revealed partial decomposition of FePS(3) with subsequent formation of iron sulfide phases poorer with sulfur element. The FePS(3) of single crystalline phase exhibited higher hydrogen sorption capacity at different temperatures than the less ordered crystalline phase. Hydrogen capacity was reduced by cycling as the interlayer gap shrinks. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.