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Another Advance on the Road to Spintronics

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Alexander Gray and Charles Fadley

Alexander Gray, left, and Charles Fadley at Beamline 9.3.1 of Berkeley Labs Advanced Light Source where they are now carrying out HARPES experiments.

Credit: Roy Kaltschmidt, Berkeley Lab

Researchers say spintronic technology could be used to make dilute magnetic semiconductors by adding a small amount of magnetic atoms to normal semiconductors, rendering them ferromagnetic.

Scientists at the Lawrence Berkeley National Laboratory are using a technique called Hard x-ray Angle-Resolved PhotoEmission Spectroscopy (HARPES) to investigate the bulk electronic structure of gallium manganese arsenide (GaMnAs), a prototypical dilute magnetic semiconductor. They used HARPES to investigate the electronic bulk structure of GaMnAs. As a semiconductor, gallium arsenide is second only to silicon in widespread use and importance.

"Right now the temperature at which gallium manganese arsenide operates as a dilute magnetic semiconductor is 170 Kelvin," says physicist Charles Fadley, who led the development of HARPES and contributed to the research. "Understanding the actual mechanism by which the magnetic moments of individual manganese atoms are coupled so as to become ferromagnetic is critical to being able to design future materials that would operate at room temperature."

HARPES studies are now underway at Berkeley Lab's Advanced Light Source using the Multi-Technique Spectrometer/Diffractometer endstation at the hard x-ray photoemission beamline.

From Lawrence Berkeley National Laboratory
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Abstracts Copyright © 2012 Information Inc., Bethesda, Maryland, USA 


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