FLUXCAP: A flux-coupled ac/dc magnetizing device

TL;DR

FLUXCAP is a compact, low-power magnetic field device that uses flux capture from a rotating magnet to generate and rapidly sweep magnetic fields for small sample experiments.

Contribution

This paper introduces FLUXCAP, a novel flux-coupled magnetizing device offering fast, adjustable magnetic fields with low power consumption and compact design, suitable for local probe station applications.

Findings

Produces magnetic fields from -400 to +400 mT with <1 mT resolution

Achieves ramping rates up to 10 T/s

Effectively studies magnetotransport in nanoscale spin-valve devices

Abstract

We report on an instrument for applying ac and dc magnetic fields by capturing the flux from a rotating permanent magnet and projecting it between two adjustable pole pieces. This can be an alternative to standard electromagnets for experiments with small samples or in probe stations in which an applied magnetic field is needed locally, with advantages that include a compact form-factor, very low power requirements and dissipation as well as fast field sweep rates. This flux capture instrument (FLUXCAP) can produce fields from -400 to +400 mT, with field resolution less than 1 mT. It generates static magnetic fields as well as ramped fields, with ramping rates as high as 10 T/s. We demonstrate the use of this apparatus for studying the magnetotransport properties of spin-valve nanopillars, a nanoscale device that exhibits giant magnetoresistance.