Mapping spatial variations of the coercivity on patterned magneto-optical materials

2007

MRS Proc.

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In this paper, we present a direct method to analyze the mechanism of magnetic domain reversal for a series of amorphous Dy x (FeCo) 1-x magnetic thin films and whereby we obtained the distributions of the coercivities and interaction fields from 90,000 measurements of the microhysteresis loops. The standard deviations of the coercivity and the interaction field distributions, σ i and σ k, can be estimated by fitting the experimental data with the Gaussian-Preisach function. The results show that the interaction field decreases as Dy composition approaches the compensation point. The reversal mechanism is dominated by nucleation when σ i is smaller than σ k . The relationships between the magnetization reversal and interaction field strength are discussed.

Section: Introductionmentioning

confidence: 99%

Analysis Interaction Field Strength and Spectrum from Microhysteresis Loops

2007

MRS Proc.

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Micromagnetic study of magnetization reversal in patterned DyFeCo thin films

Physica Status Solidi (a)

et al. 2007

Magnetization reversal in patterned perpendicular anisotropic DyFeCo films was investigated using micromagnetic simulations. The model consists of a square film of dimension 1 μm × 1 μm × 50 nm and a circular hole of diameter 500 nm on the top surface, with depth varying from 0‐30 nm. The results show that for shallower holes the coercivity decreases rapidly with the hole depth, but for the deeper holes, the coercivity in the hole region is much larger than in the land region. Further analysis indicates the variation in coercivity is due to the narrow transition region formed near the hole boundary where the magnetization has a tilted distribution determined mainly by the competition between anisotropy and exchange interactions. The simulation results are qualitatively consistent with our previous experimental outcome. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

The effect of hole depth on the coercivity distribution and domain structure for DyFeCo thin films

Journal of Applied Physics

et al. 2005

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In our previous studies, we indicated that the coercivity of patterned magneto-optical thin film is quite different from nonpatterned samples. However, we only compared the hysteresis loop bulk measurements of the samples. In this study, we measured the microhysteresis curves at an arbitrary position while coercivity distribution was mapped, and observed submicron images of the remnant state of domain reversal patterns. The spatial variations of the coercivity over several depths of hole arrays barrier on patterned film will be reported.