Lattice location of deuterium in lutetium

The lattice location of deuterium in implanted and in thermally diffused h.c.p. α-LuD0.01 crystals is determined by channeling methods. In the diffused samples, the predominant D position is the tetrahedral site in the whole investigated temperature range of 25 to 425 K. In the implanted specimens, the preferred D location is also the T-site up to 280 K; above this temperature, the deuterium atoms disappear gradually, probably by diffusion into the bulk, after detrapping from implantation defects. Generalising from other results, it is proposed that the T-site is the stable position of hydrogen in solid solution in h.c.p. metals.