Magnetic-Resonance Spectra of Mn in Au and Pd

The electron-paramagnetic-resonance properties of Mn impurities in Au and Pd are reported for the first time. A small positive $g$ shift was observed for Mn in Au. Although this result is in agreement with the Mn $g$ shift in Ag and Cu the Mn linewidth in Au at 20°K was 725 G, which is more than five times larger than in Ag and Cu. It was found that, in contrast to the Gd resonance, nonmagnetic impurities such as Ag in Au broaden the Mn line appreciably. A large positive $g$ shift has been observed for Mn in Pd. This shift is explained by a positive exchange interaction $\overline{J}\left(\mathrm{S}·\mathrm{s}\right)$ of the Mn impurities with the Pd valence band and is opposite in sign to the exchange interaction observed previously for Gd in Pd. Comparison of the Mn additional $g$ shifts with the additional Gd $g$ shifts produced by the presence of other rare-earth impurities in Pd confirms the exchange-interaction mechanism and the polarization of the valence electrons by the rare-earth impurities.