Growth of palladium nanocrystallites induced by hydrogen-ion irradiation at low energies

Crystalline particles of palladium with nanometer dimensions are known to grow on polycrystalline Pd interacting with low-energy hydrogen or deuterium ions. This so-called “ion-induced crystallite growth” (IICG) is reviewed briefly. In IICG, Pd crystallites disperse on an amorphous medium termed “matrix”, which, like volcanic magma, emerges from the subsurface through a surface crater or fissure. The crystallites are mostly spherical, presumably because of their melting during hydrogen irradiation. The target temperatures required for this solid-to-liquid transformation is around one-third of the melting point of Pd; absorbed hydrogen ions might dramatically reduce the melting temperature of the crystallites.