Nuclear electric quadrupole interactions of 111Cd in the heavy-fermion compound CeCoIn5 compounds.

M. FORKER; P. R. J. SILVA; E. BAGGIO-SAITOVICH; H. SAITOVICH; S. RAMOS; R.E. ALONSO; L. A. ERRICO; M. A. TAYLOR

La Plata

Encuentro; Humboldt Kolleg: Argentina – Alemania: 100 años de cooperación científica en Física; 2011

The nuclear electric quadrupole interaction of the probe nucleus 111Cd on the Insites of the heavy-fermion compound CeCo(In1-xSnx)5; x = 0.01 has been investigatedin the temperature range 15 ≤ T ≤ 290 K by perturbed angular correlation spectroscopy.Single crystals of CeCo(In1-xSnx)5 grown from an In flux by combining stoichiometricamounts of Ce and Co with excess In were doped with the PAC probes 111Cd bydiffusion at 700 K of radioactive 11I In from a carrier-free solution of 111InCl3 into thehost lattice.Apart from a sizeable fraction of non-reacted In metal, the PAC spectra containcontributions of two In-sites related to the CeCoIn5 structure, an axial symmetric and anasymmetric site. The 11ICd electric field gradient (EFG) of these sites differssubstantially from the two EFG values determined by NQR measurements for the probe115In on sites 1c and 4i of CeCoIn5, both with respect to strength and symmetry. For aninsight into the mechanism leading to these differences, an ab initio study of thestructural and electronic properties of Cd on In sites of CeCoIn5 is under way.