Possible Mechanism of Superconductivity in PuCoGa5 Probed by Self-irradiation Damage

Measurements of the electrical resistivity of a polycrystalline PuCoGa5 sample reveal significant modifications of the superconducting properties as a function of time, due to the increase of defects and impurities resulting from self-irradiation damage. More than four years of aging were necessary to detect a deviation from linearity in the time dependence of the critical temperature. The observed behavior is understood in the framework of the Eliashberg theory, confirming the ¿dirty¿ d-wave character which was already suggested by nuclear magnetic resonance. We show that experimental data accumulated so far can be well reproduced by assuming a phononic mechanism for superconductivity, with reasonable values of the electron-phonon coupling and Coulomb pseudopotential. Further experiments are then required to assess the role of spin fluctuations in stabilizing the superconducting state in this compound.

UMMARINO G. A.;  GRIVEAU Jean-Christophe;  WASTIN Franck;  COLINEAU Eric;  REBIZANT Jean;  MAGNANI Nicola;  CACIUFFO Roberto;  JUTIER F.; 

2008-03-07

AMERICAN PHYSICAL SOC

JRC43898

1098-0121,   

https://publications.jrc.ec.europa.eu/repository/handle/JRC43898,   

10.1103/PhysRevB.77.024521,