Superconductivity and Mössbauer Effect in Actinides

Superconductivity, discovered more than 100 years ago, still remains challenging for condensed matter physics, 50 years after the BCS theory on superconductivity. Actinide materials and their 5f electrons play an important role in this field, with a large number of uranium heavy fermion magnetic superconductors reported in the last three decades and, more recently, the discovery of transuranium unconventional superconductors : PuCoGa5, PuRhGa5, PuCoIn5 and NpPd5Al2. The paramagnetic heavy fermion NpPd5Al2 (Tc = 4.9K and  = 200 mJ mole-1 K-2) is the only neptunium-based superconductor known so far. A recent novel model has predicted a possible temperature-dependence with an extremum of the charge density in NpPd5Al2. In order to check this prediction and using the 237Np Mössbauer resonance, we have measured the temperature dependence of the isomer shift of NpPd5Al2 with the best experimental accuracy possible and found a small extremum.

HEN Amir;  HALEVY Itzhak;  ORION I.;  COLINEAU Eric;  ELOIRDI Rachel;  GRIVEAU Jean-Christophe;  GACZYNSKI Piotr;  KLIMCZUK Tomasz;  SANCHEZ J.P.;  SHICK A.B.;  CACIUFFO Roberto; 

2013-10-02

Dipartimento di Chimica e Chimica Industriale (DCCI) , Università di Genova

JRC79960

http://jda2013.spin.cnr.it,    https://publications.jrc.ec.europa.eu/repository/handle/JRC79960,