Comparison of Exchange Interactions in II-VI, III-V, and I-II-V Dilute Magnetic Semiconductors: Density Functional Approach
J. Mašeka, J. Kudrnovský, a, F. Mácaa and T. Jungwirthb, c
aInstitute of Physics, AS CR, Na Slovance 2, 182 21 Prague 8, Czech Republic
bInstitute of Physics, AS CR, Cukrovarnická 10, 162 53 Prague 6, Czech Republic
cSchool of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
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Received: 17 06 2006;
We use the coherent potential method based on the density-functional theory to compare the electronic structures and magnetic characteristics of mixed crystals (Ga,Mn)As, (Zn,Mn)Se, and Li(Zn,Mn)As. We show that, with the same degree of doping, the magnetic behavior of these materials is very similar, reflecting the similarity of their electronic structures. In particular, the superexchange in (Ga,Mn)As is as strong as in (Zn,Mn)Se and the ferromagnetic coupling in all these dilute magnetic semiconductors becomes dominant only at sufficient concentration of the holes. Remarkably, we find that ferromagnetic state appears not only in p-type, but also in n-type materials at a comparable level of doping. Although obtaining strongly n-type doped III-V dilute magnetic semiconductors is improbable, Li(Zn,Mn)As seems to be a promising candidate for a ferromagnetic n-type semiconductor.
DOI: 10.12693/APhysPolA.110.249
PACS numbers: 71.15.Ap, 71.20.Nr, 71.55.Eq, 75.50.Pp