Field ion microscopic observations showed that the diffusion rate of Pt atoms on (100) was appreciably reduced when the surface was exposed to H. Thus, a H partial pressure of 10-10Torr caused the exchange diffusion rate to decrease by 3 orders of magnitude over 2 to 3h. Higher pressures suppressed exchange displacements to the point where hopping displacements became energetically accessible. The ability to influence both displacement rate and transport mechanism indicated that H could be used to control thin-film growth at the atomic level.

Hydrogen Inhibition of Exchange Diffusion on Pt (100) G.L.Kellogg: Physical Review Letters, 1997, 79[22], 4417-20