Spatially resolving variations in giant magnetoresistance, undetectable with four-point probe measurements, using infrared microspectroscopy

Journal Article · Mon Oct 15 00:00:00 EDT 2012 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4760282· OSTI ID:22080492

Kelley, C S; Thompson, S M; Illman, M D ^[1]; LeFrancois, S; Dumas, P ^[2]

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1. Department of Physics, University of York, Heslington, York, North Yorkshire YO10 5DD (United Kingdom)
2. SMIS Beamline, SOLEIL Synchrotron, L'Orme des Merisiers, Saint-Aubin, Paris, BP 48 91192 (France)

Magnetorefractive infrared (IR) microspectroscopy is demonstrated to resolve spatial variations in giant magnetoresistance (GMR) and, by modelling, provide an insight into the origin of the variations. Spatial variations are shown to be masked in conventional four-point probe electrical or IR spectral measurements. IR microspectroscopy was performed at the SMIS beamline at the SOLEIL synchrotron, modified to enable measurements in magnetic fields. A GMR gradient was induced in a CoFe/Cu multilayer sample by annealing in a temperature gradient. Modelling revealed that variations in GMR at 900 Oe could be attributed to local variations in interlayer coupling locally changing the switching field.

• OSTI ID: 22080492
• Journal Information: Applied Physics Letters, Vol. 101, Issue 16; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANNEALING
COBALT ALLOYS
COPPER
COUPLING
INFRARED SPECTRA
IRON ALLOYS
LAYERS
MAGNETIC FIELDS
MAGNETO-OPTICAL EFFECTS
MAGNETORESISTANCE
PROBES
SIMULATION
SYNCHROTRONS
TEMPERATURE GRADIENTS