Gate-controlled magnetic properties of the magnetic semiconductor (Zn,Co)O.
Electric field-controlled ferromagnetism of (Zn,Co)O is demonstrated via anomalous Hall effect measurements. The electron carrier concentration in this material is 1.65x10(20) cm(-3) as measured via ordinary Hall effect at 4 K, and an anomalous Hall effect is observed up to 6 K, but with no hysteresis at any temperature. With positive electric gate field, the carrier concentration is increased by approximately 2%, resulting in a clear magnetic hysteresis at 4 K. The ability to reversibly induceeliminate ferromagnetism by applied gate field alone, measured via the effect on the carriers, is a clear sign of carrier-induced ferromagnetism in this system.
Lee
H-J
HJ
Department of Physics, University of California, Berkeley, Berkeley, California 92093, USA.
Helgren
E
E
Hellman
F
F