Spin-flip scattering for the electrical property of metallic-nanoparticle thin films

Abnormal breaks in the resistance-temperature (R-T) curves for granular thin films containing numerous metallic particles have been observed recently. We propose an extra contribution to the resistivity arising from the spin-flip scattering (the Kondo effect) among the spins of conducting electrons and the local magnetic moments of metallic nanoparticles. Each metallic nanoparticle in a granular thin film behaves like a local spin S in analogy to the well localized magnetic moments in dilute alloys. We also find that a log-normal distribution of particle sizes will cause the sharp break in the R-T curve to become broad. With sufficient fitting parameters we can explain the breaks around 120 K.