Se-77 and Cu-63 NMR studies of the electronic correlations in CuxTiSe2 (x=0.05, 0.07)

Abstract

We report a Se-77 and Cu-63 nuclear magnetic resonance (NMR) investigation on the charge-density-wave (CDW) superconductor CuxTiSe2 (x = 0.05 and 0.07). At high magnetic fields where superconductivity is suppressed, the temperature dependence of Se-77 and Cu-63 spin-lattice relaxation rates 1/T-1 follow a linear relation. The slope of Se-77 1/T-1 versus T increases with the Cu doping. This can be described by a modified Korringa relation which suggests the significance of electronic correlations and the Se 4p- and Ti 3d-band contribution to the density of states at the Fermi level in the studied compounds.