Title :
Magnetotransport in Ferromagnetic (Ga, Mn)As and (Ga, Mn)N Pn-Diodes
Author :
Holmberg, H. ; Lebedeva, N. ; Novikov, S. ; Kuivalainen, P. ; Malfait, M. ; Moshchalkov, V.V.
Author_Institution :
Dept. of Electr. & Commun. Eng., Helsinki Univ. of Technol., Espoo
Abstract :
GaAs and GaN pn-junctions are fabricated with Mn-doped ferromagnetic layers on top of nonmagnetic substrates. In the case of heavily doped (Ga,Mn)As/GaAs p++n++-junctions (Zener diodes) the tunneling current becomes magnetic field dependent at low temperatures. This can be explained by a model based on the valence band splitting due to the exchange interaction between the hole spins and the localized spins of the Mn atoms. In the pn-junctions with more lightly doped nonmagnetic regions in the (Ga, Mn)N and (Ga, Mn)As diodes, no magnetic field dependence in the I-V characteristics is observed, probably due the absence of ferromagnetism in the depletion region of the p+n-junctions
Keywords :
III-V semiconductors; ferromagnetic materials; ferromagnetism; gallium compounds; magnetic semiconductors; magnetic tunnelling; magnetoresistance; semiconductor diodes; GaAs; GaN; Zener diodes; depletion region; ferromagnetic layers; ferromagnetic pn-diodes; ferromagnetism; hole spins; magnetic field; magnetic semiconductors; magnetoresistance; magnetotransport; nonmagnetic regions; nonmagnetic substrates; pn-junctions; spin-dependent tunneling; tunneling current; valence band splitting; Electrons; Gallium arsenide; Gallium nitride; Gold; Magnetic semiconductors; Magnetic tunneling; Molecular beam epitaxial growth; Physics; Semiconductor diodes; Temperature; Magnetic semiconductors; magnetoresistance; spin-dependent tunneling;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2006.878849
