Surface phonon scattering in the electrical resistivity on Co/Ni superlattices

The effect of surface phonon scattering on the electrical resistivity has been observed in Co/Ni superlattices, with reproducible film microstructure independent of the film thickness. The temperature dependent part of the resistivity increases rapidly with decreasing film thickness for films thinner than the electronic mean free path. The resistivity shows a universal behavior well characterized by the Bloch-Gruneisen model. The deviation from the bulk resistivity can be explained by a reduced surface Debye temperature and additional surface phonon modes.