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. ALONSO; L. A: ERRICO; M. A. TAYLOR

La Plata

Congreso; Humboldt Kolleg: Argentina ? Alemania: 100 años de cooperación científica en Física; 2011

Depto de Fisica - Fundación Von Humboldt

The nuclear electric quadrupole interaction of  the probe nucleus 111Cd  on the In sites of the heavy-fermion compound  CeCo(In1-xSnx)5; x = 0.01  has been investigated in 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 stoichiometric amounts of Ce and Co with excess In were doped with the PAC probes 111Cd by diffusion at 700 K of radioactive 111In  from a carrier-free solution of 111InCl3 into the host lattice.  Apart from a sizeable fraction of non-reacted In metal, the PAC spectra contain contributions of two In-sites related to the CeCoIn5 structure, an axial symmetric and an asymmetric site. The 111Cd electric field gradient (EFG) of these sites differs substantially from the two EFG values determined by NQR measurements for the probe 115In on sites 1c and 4i of CeCoIn5, both with respect to strength and symmetry. For an insight into the mechanism leading to these differences, an ab initio study of the structural and electronic properties of 111Cd on In sites of CeCoIn5 is under way.