Stray field of a Landau magnetization pattern

Abstract

We present experiments and micromagnetic simulations on Hall micromagnetometry of magnetic vortices. The magnetization reversal in a 2×2 μm2 Permalloy square of 20 nm thickness is investigated at liquid helium temperatures. Nucleation, displacement, and annihilation of the vortex state in an external magnetic field are observed by detecting its stray field. The findings are corroborated by images taken with a magnetic-force microscope at room temperature. The experimental data are compared to micromagnetic simulations.

Temperature-dependent dynamics of stochastic domain-wall depinning in nanowires

“…In this respect, ballistic Hall micromagnetometry provides a number of advantages. This method was first introduced in 1997 by Geim et al for the investigation of phase transitions in mesoscopic superconductors [15,16] and has been employed successfully to investigate ferromagnetic microstructures [17][18][19][20][21][22][23] and nanostructures [24][25][26]. Its high sensitivity was demonstrated by the detection of domain-wall movement in the Peierls potential [27] and the observation of Barkhausen jumps in garnet films [28].…”

Inductive detection of magnetic vortex gyration

“…1. The stray fields of the domains and the domain walls can be detected rather than the stray field of the vortex itself 23 because of its small extension of a few nanometers. 24 The detection of the gyration in a square by an induction loop requires the deposition of several materials, laterally defined by electron-beam lithography.…”