We report on our studies of Ni transport induced by 300 keV Xe irradiation of 25 nm Ni films evaporated on thermally grown SiO2 at Xe fluences of 1013-1016 cm-2 and at temperatures of 300-750 K during irradiation. Cross-sectional TEM, and selective etching combined with 2 MeV He backscattering spectrometry and ESCA were used to profile the Xe and Ni within the SiO2. At 300 K, backscattering shows cascade mixing dominates, although only ~ 1/35 that predicted by cascade theory, with most of the Ni in the SiO2 contained in a resolution limited peak adjacent to the SiO2 interface. TEM shows that this Ni is contained in a 5 nm band, 5 nm below the interface as Ni oxide clusters. Examination of the satellite structure of the Ni 2p line by XPS also shows this band is predominantly Ni2+. At 750 K, the near-surface peak vanishes and only recoil implantation is evident. Ni0 is evident by XPS in samples irradiated at 300 K, though not at higher temperatures. We explain our results in terms of phase separation during cooling of the collision cascade.