Giant Magneto Resistance

The resistance of a GMR sample changes in the presence of a magnetic field and is the basis of the read head in computer hard drives.

The resistance of a GMR sample changes in the presence of a magnetic field created by a magnetic stir bar.

What is the orientation of this GMR sensor? The LED lights when the sensor detects a magnetic field.

A GMR sensor responds to a changing magnetic field. The LED lights when the sensor detects a magnetic field.

What is the pattern of the magnetic field on a refrigerator magnet? The LED lights when the sensor detects a magnetic field.

An electromagnet produces a stronger field with an iron core. The LED lights when the sensor detects a magnetic field.

Animation of current flow through a GMR material. Electron passage is impeded by electrons of opposite spin.
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Model of electron spin alignment in a GMR material. The alignment changes upon application of a magnetic field.

Model of electron spin alignment in a GMR material. The alignment changes upon application of a magnetic field. When the spins align the laser beam coming from the left can pass through.


Exploring the Nanoworld   |   MRSEC Nanostructured Interfaces
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This page created by George Lisensky, Beloit College.  Last modified July 25, 2008 .