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Name: Briana R.
Status: student
Age: 17
Location: N/A 
Country: N/A
Date: 11/22/2004

Our physics class is researching GMRs and magnetic fields and we were wondering if you could tell us how to make one. How do they work? Anything information you could give us would me amazing.

The GMR effect depends on sandwiching a thin non-ferromagnetic layer between two magnetic materials. Because your class has been researching them, you have discovered that "thin" means only a few atoms thick. It is not easy to make a thin layer a few atoms thick because it requires laboratory vacuum deposition equipment.

There is one company that makes GMR chips that sense magnetic fields ( , but just having a manufactured chip would not be interesting because the company has done all the engineering for you.

The problem is that much of the "easy to make" physics was done fifty or 100 years ago, and some more recent discoveries, like GMR, transistors, hall effect, and nanotubes, require fancy lab equipment to make or examine. However, it is possible to still investigate physics phenomena using household items like laser pointers, meters, diffraction gratings, lenses, and so on.

Bob Erck

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