Domain wall resonance and stability in magnetite.

Abstract

This paper introduces a technique to the study of multidomain remanence which has not previously seen application in rock magnetism: domain wall resonance (DWR). We show that the variation of the DWR spectra with different RF power levels gives useful, and hitherto unavailable, information about the nature of the potentials which govern domain wall motion. In particular, we demonstrate that these potentials must rise less rapidly than a harmonic potential, contrary to previous models. The possible mechanisms for domain wall pinning are discussed and it is concluded that the likeliest candidates for pinning sites in our samples, at least, are large nonuniform dislocation arrays. Finally, we suggest a possible method for selectively demagnetizing multidomain grains based on DWR techniques.-Authors