Local fields at nonmagnetic impurity sites in a perovskite La 0 . 7 Ca 0 . 3 MnO 3

Abstract

The magnetic hyperfine field and electric field gradient at the 111Cd( $\leftarrow ^{\mathrm {111m}}$ Cd) and 111Cd( $\leftarrow ^{\mathrm {111}}$ In) probe nuclei introduced in a perovskite manganese oxide La0.7Ca0.3MnO3 (T C ∼ 250 K) were measured for the study of the local magnetism and structure by means of time-differential perturbed angular correlation spectroscopy. In the ferromagnetic phase at 77 K, a very slight supertransferred magnetic hyperfine field (SMHF) (< 0.014 T) combined with a well-defined electric field gradient was observed at the nonmagnetic 111Cd nucleus on the La/Ca A site. This observation suggests that the large magnetic hyperfine field (B h f = 6.9 T) measured, in our previous work, at the 140Ce probe nucleus on the A site originates from the contribution of a 4f spin oriented by the SMHF from adjacent Mn ions.