Investigation of the local magnetism at rare-earth sites in RAg (R rare-earth) intermetallic compounds using perturbed gamma-gamma angular correlation spectroscopy

Time differential perturbed gamma-gamma angular correlation (TDPAC) technique was used to measure the magnetic hyperfine field (mhf) at rare earth sites in intermetallic compounds RAg (R = Dy, Gd, Ho, Nd, Tb) in order to study the behavior of the mhf with 4f-electron density variation. 140Ce was used as probe nuclei in the TDPAC measurements, which was carried out in the temperature range of 10 K to 300 K. The results of the temperature dependence of the mhf show a standard antiferromagnetic behavior below the magnetic order temperature but, for lower temperatures, it was observed a sharp deviation from the expected Brillouin-like behavior with an increase of the mhf values. The values of the mhf for each compound at the lowest temperature just above the deviation were compared to the respective projection of the rare-earth spin on the total angular momentum J. The results showed to follow a similar behavior when compared to those for the magnetic moment of the compounds. (author)