New hydride phase with a deformed FCC structure in the Ti–V–Mn solid solution–hydrogen system

We investigated the hydriding properties and crystal structure of a Ti–V–Mn solid solution alloy by means of P–C isotherm and X-ray diffraction (XRD) measurements. We found three hydride phases with a BCC, a deformed FCC and an FCC structure. The lattice constant of the deformed FCC is 0.407 nm, one axis of which is reduced by about 4%, which has not been reported so far. Its single-phase region extends over a hydrogen content between 0.8 and 1.0 H/M in absorption at 298 K. The lower plateau observed in the P–C isotherm due to the formation of the deformed FCC hydride phase increases the effective hydrogen capacity by decreasing the amount of hydrogen that would have remained in the alloy after the usual desorption process.