Hydrogen control of ferromagnetism in a dilute magnetic semiconductor.
We show that upon exposure to a remote dc hydrogen plasma, the magnetic and electronic properties of the dilute magnetic semiconductor Ga1-xMnxAs change qualitatively. While the as-grown Ga1-xMnxAs thin films are ferromagnetic at temperatures T less, similar 70 K, the samples are found to be paramagnetic after the hydrogenation, with a Brillouin-type magnetization curve even at T=2 K. Comparing magnetization and electronic transport measurements, we conclude that the density of free holes p is significantly reduced by the plasma process, while the density of Mn magnetic moments does not change.
Goennenwein
Sebastian T B
ST
Walter Schottky Institut, Technische Universität München, Am Coulombwall 3, D-85748 Garching, Germany. goennenwein@tnw.tudelft.nl
Wassner
Thomas A
TA
Huebl
Hans
H
Brandt
Martin S
MS
Philipp
Jan B
JB
Opel
Matthias
M
Gross
Rudolf
R
Koeder
Achim
A
Schoch
Wladimir
W
Waag
Andreas
A