Kerr microscopy studies of the effects of bending stress on galfenol

Abstract

This work deals with using a magneto-optic Kerr effect (MOKE) microscope to optically analyze the evolution of magnetic domains in a rolled and Goss textured galfenol (Fe81Ga19 + 1.0% NbC) sample when subjected to a bending stress. The initial magnetization state of the cantilevered sample was fixed along its length by a 0.3 T permanent magnet. The magnetic state was monitored with the MOKE microscope as a tip load was applied to bend the sample. The magnetic state of galfenol depends on its magneto-elastic properties. A finite element model that incorporates an energy based formulation of magnetostriction [W. D. Armstrong, J. Magn. Magn. Mater. 263(1–2), 208–218 (2003)] was used to investigate the stresses in the sample and the corresponding change in the magnetic induction as bending occurred. A qualitative comparison with the domain pictures is presented, and the experimental micromagnetic behavior results are shown to correlate well to the macro scale bending stress and magnetization results obtained in the FEM simulations.

Document Details

Document Type
Pub Defense Publication
Publication Date
Feb 26, 2014
Source ID
10.1063/1.4865468

Entities

People

  • Alison B. Flatau
  • Ganesh Raghunath
  • Michael Marana
  • Suok-min Na

Organizations

  • Office of Naval Research
  • University of Maryland

Tags

Readers

  • Materials Science and Engineering.
  • Structural Dynamics.
  • Structural Health Monitoring of Composite Structures.