  We report 4-probe resistivity measurements of cold-rolled Ni and Fe during
100 MeV oxygen ion irradiation, at 300K. The resistivity shows increase and
saturation, marked by jumps. Employing 200 MeV silver ion irradiation of Fe and
Si(100) and topographically identifying strain at an artificial interface in
the latter, we assign the resistivity behavior to atomic rearrangements arising
from dissipation of incident ion energy at internal interfaces of Ni and Fe,
with positive feedback.}
