Exchange Narrowing of Fine Structure in Dilute Magnetic Alloys: Mg: Gd

Abstract

The magnetic-resonance spectrum of dilute Mg: Gd alloys is analyzed using the full coupled localized-conduction-electron transverse-susceptibility expression derived by Barnes. An analysis of the significance of the individual terms in the susceptibility matrix is presented, along with a physical interpretation of exchange narrowing of fine-structure splittings in dilute magnetic alloys. A value of $D=140\mathrm{}$ G for the fine-structure parameter is extracted from a fit to the theory. Comparison is made with a moment analysis utilized previously.