Delafossite oxides ABO2 (A = Ag, Cu; B = Al, Cr, Fe, In, Nd, Y) studied by perturbed-angular-correlation spectroscopy using a 111Ag(β-)111Cd probe

The electric-field gradient (EFG) at Cd-111 nuclei dilutely substituting an A cation site in delafossites A(+1)B(+3)O(2) has been measured using a perturbed-angular-correlation technique. The radioactive isotope Ag-111(beta(-))Cd-111 was used as the hyperfine probe and introduced into the samples by thermal diffusion. The EFG's measured using a Ag-111 --> Cd-111 probe are compared with those measured using the In-111 --> Cd-111 probe and with the calculated values using the point-charge model including the local distortion introduced by the probe. The results are also discussed in terms of a previously observed correlation between the electric-field gradient and the cation-oxygen bond length in these delafossites and other binary oxides. [S0163-1829(98)01329-0].