A two-stage hydrogen release of 4.9 wt.% was observed on a mixture of Mg(NH2)(2) and CaH2 at 1:2 molar ratio. The H-2 desorption in the temperature range from room temperature to 260 degrees C was recyclable, which was observed by temperature-programmed-desorption (TPD), volumetric measurement and Fourier transform infrared (FT-IR). At high temperature, a ternary nitride CaMg2N2 and a solid solution of CaNH/Ca2NH, characterized by X-ray diffractometry (XRD), were formed. (c) 2006 Elsevier B.V. All rights reserved.