Stray-field investigation on permalloy nanodisks

Abstract

The stray field of individual nanostructured permalloy (Py) disks has been measured by means of a sub-μm Hall magnetometer which incorporates a ballistic two-dimensional electron system. The circular nanomagnets have diameters of d=500, 600, and 700 nm and thickness of t=20 nm. The characteristic shape of the experimental Hall curves can be explained by the behavior expected from micromagnetic simulations. They indicate that near remanence the disks are in the vortex phase. For the largest Py nanomagnet, if saturated, an averaged value of the stray field of 36 mT is measured in our 300 nm wide Hall sensor.

Scalable parallel micromagnetic solvers for magnetic nanostructures

“…This characteristic behavior has also been found experimentally using Hall-micromagnetometry by Hengstmann et al [115], who measured the stray field of individual permalloy disks using a sub-µm Hall magnetometer. The hysteresis loops of arrays of Supermalloy nanomagnets have been measured by Cowburn et al [110] using the Kerr effect.…”

“…For about −70 kA/m the vortex is pushed out of the nanodot (annihilation: Fig. 9.10(d)) and we find the second jump in the hysteresis curve to (almost) saturation.This characteristic behavior has also been found experimentally using Hall-micromagnetometry by Hengstmann et al [115], who measured the stray field of individual permalloy disks using a sub-µm Hall magnetometer. The hysteresis loops of arrays of Supermalloy nanomagnets have been measured by Cowburn et al [110] using the Kerr effect.…”

Hall magnetometry on a ferromagnetic nanoring

“…1(b). This suggests that contrary to nanodisks [5] a core is not formed in the individual nanoring. This is in agreement with micromagnetic simulations which we performed using the OOMMF [6] program.…”

“…Rings had an outer diameter of 550 nm and inner holes with different widths. The Hall sensor is sensitive to the stray-field component perpendicular to the substrate plane [5]. This component varies as a function of the magnetization state of the nanorings.…”

Magnetic nanostructures for lateral spin-transport devices

“…We have fabricated nanodisks on mesoscopic 2DES and have investigated the stray-field effects [23]. The MR effect is found to be less complex if compared to rectangular micromagnets (Fig.…”