Possible pairing mechanisms of PuCoGa5 superconductor -: art. no. 104512

We examine possible pairing mechanisms of superconductivity in PuCoGa5 based on spin-fluctuations or phonons as mediating bosons. We consider experimental data of specific heat C(T) and resistivity rho(T) as input to determine a consistent scattering boson with the superconducting transition temperature of 18.5 K in PuCoGa5. Irrespective to the type of boson, the characteristic boson frequency is found to be similar to150 K from the resistivity fitting. The spin fluctuation model is most consistent with the experimental resistivity, successfully explaining the anomalous temperature dependence [similar to(T-2/150 K+T)] at low temperatures as well as the saturation behavior at high temperatures. Assuming that the pairing state is a non s-wave, the large residual resistivity rho(imp)similar to20 muOmega cmsimilar to120 K suggests that an ideally pure sample of PuCoGa5 would have a maximum T-c of 39 K.