Hydrogen absorption at room temperature in YMn2 leads to a mixture of sever
al phases with various hydrogen contents. A thermal treatment at 473 K allo
ws single-phase YMn2Hx hydrides with 0 < x less than or equal to 3.5 to be
obtained. The hydride synthesis has been studied in the case of single-phas
e YMn2D2 by in situ thermal-dependent neutron diffraction experiments. The
different steps for the formation of the single-phase deuteride are describ
ed and discussed. (C) 2000 Academic Press.