Structural Study of Low-Temperature-Implanted Ni and Pd Hydrides

In situ transmission-electron-microscopy experiments show that, as expected from previously measured transport properties, the production of Ni and Pd hydrides prepared by hydrogen implantation at 10-20 K does not destroy the host symmetry. However, contrary to their quasiequilibrium counterparts, both implanted hydrides are single phased up to $\frac{H}{M}=1\mathrm{}$. The lattice parameter varies linearly with $\frac{H}{M}$, and its value for implanted PdH is only half that of the high-pressure-charged hydride.