International Journal of Hydrogen Energy, Vol.44, No.13, 6709-6719, 2019
Cyclic stability of the C36-type TiCr2 Laves phase synthesized in the abnormal glow discharge plasma under hydrogenation
In this work, the cyclic stability of the C36-type TiCr2 Laves phase synthesized in the abnormal glow discharge plasma was investigated. Melting of titanium-chromium metallic powders by the glow discharge plasma leads to the formation of the TiCr2 hexagonal C36 Laves phase with lattice parameters a = 4.928 angstrom and c = 15.983 angstrom. The hydrogenation-dehydrogenation method was used for crushing to increase the effective sorption capacity of the C36-type TiCr2 Laves phase. The stable hydride TiCr2Hx (x <= 0.5) phase of structural polytype C36 is formed during the first absorption/desorption cycle at the temperature of 30 degrees C. After 15 cycles hydride with the stoichiometric composition close to the TiCr2H0.5 phase of C36 polytype with lattice parameters: a = 4.961 angstrom and c = 16.224 angstrom was observed by XRD analysis. The hydrogen is localized in the crystal lattice in three main states: in a solid solution trapped by defects, open volume defects, and in the form of hydrides. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.