Resistivity saturation in PrFeAsO1-xFy superconductor: evidence of strong electron-phonon coupling

We have measured the resistivity of PrFeAsO1-xFy samples over a wide range of temperature in order to elucidate the role of electron-phonon interaction on normal- and superconducting-state properties. The linear T dependence of. above 170 K followed by a saturation-like behavior at higher temperature is a clear signature of strong electron-phonon coupling. From the analysis of the T dependence of., we have estimated several normal- state parameters that are useful for understanding the origin of superconductivity in this system. Our results suggest that Fe-based oxypnictides are phonon-mediated BCS superconductors like Chevrel phases and A15 compounds.