Transport dynamics of superparamagnetic microbeads trapped by mobile magnetic domain walls

The dynamics of fluid-borne superparamagnetic bead transport by field-driven domain walls (DWs) in submicrometer ferromagnetic tracks is studied experimentally together with numerical and analytical modeling. A combination of micromagnetic modeling and numerical calculation is used to determine the...

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Bibliographic Details
Main Authors: Rapoport, Elizabeth, Beach, Geoffrey Stephen
Other Authors: Massachusetts Institute of Technology. Department of Materials Science and Engineering
Format: Article
Language:en_US
Published: American Physical Society 2014
Online Access:http://hdl.handle.net/1721.1/88746
Description
Summary:The dynamics of fluid-borne superparamagnetic bead transport by field-driven domain walls (DWs) in submicrometer ferromagnetic tracks is studied experimentally together with numerical and analytical modeling. A combination of micromagnetic modeling and numerical calculation is used to determine the strength of bead-DW interaction for a range of track geometries and bead sizes. The maximum DW velocity for continuous bead transport is predicted from these results and shown to be supported by experimental measurements. Enhancement of the maximum velocity by appropriate material selection or field application is demonstrated, and an analysis of the source of statistical variation is presented. Finally, the dynamics of bead-DW interaction and bead transport above the maximum DW velocity for continuous DW-mediated bead transport is characterized.