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Magnets for Energy and Recording

In the area of permanent magnets, we are exploring the reversal mechanism of hard permanent magnets in order to improve their utility for alternative energy purposes. We strive to develop stronger permanent magnets with higher Curie temperatures and lower rare-earth content. We study the competition of domain wall propagation and nucleation in sintered and nanostructured rare earth magnets. We are analyzing hard-soft composite structures.

In the area of magnetic recording, we are collaborating with Kai Liu’s group, studying graded columnar media and nanopatterned media to achieve higher density, lower energy recording systems. Among others, we are focusing on HAMR and bit patterned media, and the study of the L10 phase of FePt.

How

Toyota supports our collaborative effort with T. Schrefl and M. Winklhofer. This is a comprehensive research project, in close interaction with several experimental groups. We use the following tools:
- the FEMME finite element LLG code for micromagnetics
- the OOMMF code for micromagnetics
- the FORC analysis in the mean field + local corrections framework
- analytic methods in one dimension
- elastic rubber band method for determining energy barriers.

In magnetic recording, we are collaborating with Kai Liu's group, and use micromagnetic, FORC and analytic tools.

Talks

Papers

FORC studies of permanent magnets. Journal of Magnetism and Magnetic Materials, 111: 07A728. (2012)

Optimizing Graded Media Magnetism and Magnetic Materials (2007)