Perturbation of magnetostatic modes observed by ferromagnetic resonance force microscopy

Authors

R. Urban, California Institute of Technology, MC 114-36, Pasadena, California
A. Putilin, California Institute of Technology, MC 114-36, Pasadena, California
P.E. Wigen, California Institute of Technology, MC 114-36, Pasadena, California
Sy_Hwang Liou, University of Nebraska-LincolnFollow
M.C. Cross, California Institute of Technology, MC 114-36, Pasadena, California
P.C. Hammel, Ohio State University, Columbus, Ohio
M.L. Roukes, California Institute of Technology, MC 114-36, Pasadena, California

Date of this Version

June 2006

Comments

Published by American Physical Society. Phys. Rev. B 73, 212410
2006. http://prb.aps.org. Copyright © 2006 American Physical Society. Permission to use.

Abstract

Magnetostatic modes of yttrium iron garnet (YIG) films are investigated by ferromagnetic resonance force microscopy. A thin-film “probe” magnet at the tip of a compliant cantilever introduces a local inhomogeneity in the internal field of the YIG sample. This influences the shape of the sample’s magnetostatic modes, thereby measurably perturbing the strength of the force coupled to the cantilever. We present a theoretical model that explains these observations; it shows that the tip-induced variation of the internal field creates either a local “potential barrier” or “potential well” for the magnetostatic waves. The data and model together indicate that local magnetic imaging of ferromagnets is possible, even in the presence of long-range spin coupling, through the introduction of localized magnetostatic modes predicted to arise from sufficiently strong tip fields.