Exchange and hyperfine interactions in Ag:Mn dilute alloys

The electron-spin resonance of dilute Ag:Mn alloys is reported for samples containing Sb and Au nonmagnetic impurities. The bottleneck is nearly broken, allowing for the extraction of the unbottlenecked g value and linewidth. These quantities, together with the Kondo lnT coefficient as measured by Jha and Jericho, are sufficient to determine the first three partial-wave exchange amplitudes. The three partial-wave amplitudes combine to give a value for the exchange Ruderman-Kittel-Kasuya-Yosida broadening of the host NMR which is only 25% smaller than that measured by Mizuno, and reanalyzed by Alloul. The d-wave amplitude is negative, and smaller in magnitude than in Cu:Mn, implying a very much lower Kondo condensation temperature for Ag:Mn as compared to Cu:Mn. The magnitude of the shift of the Mn55 hyperfine field in Ag:Mn from the insulating state is shown to be consistent with these exchange partial-wave amplitudes. The conduction-electron spin-flip relaxation rate is extracted for each of the two impurities, Sb and Au. Finally, a line-shape analysis taking into account exchange narrowing of the hyperfine splitting is shown to partially explain the concentration dependence of the "residual width" in reflection ESR, consistent with the behavior of 1Td L in transmission ESR.