Dresden 2006 – wissenschaftliches Programm
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MA: Magnetismus
MA 20: Poster: Films(1-36) Transp(37-56) Ex.Bias(57-67) Spindyn(68-80) Micromag(81-95) Particle(96-109) Imag.+Surface(110-113) Spinelectr(114-122) Theory+Micromag(123-131) Spinstr+Aniso(132-142) MagMat(143-156) Meas(157,158) MolMag+Kondo(159-162) Postdead(163-)
MA 20.119: Poster
Dienstag, 28. März 2006, 15:15–19:15, P1
Nearest neighbor exchange in Co- and Mn-doped ZnO — •Mahdi Sargolzaei1, Thomas Chanier2, Ingo Opahle1, Roland Hayn2, and Klaus Koepernik1 — 1IFW Dresden, P.O. Box 270116, D-01171 Dresden, Germany — 2Laboratoire Materiaux et Microelectronique de Provence, Faculte St. Jerome, Case 142, F-13397 Marseille Cedex 20, France
We calculate the magnetic interactions between two nearest neighbor substitutional magnetic ions (Co or Mn) in ZnO by means of density functional theory and compare it with the available experimental data. Using the local spin density approximation we find a coexistence of ferro- and antiferromagnetic couplings for ZnO:Co, in contrast to experiment. For ZnO:Mn both couplings are AFM but deviate quantitatively from measurement. That points to the necessity to account better for the strong electron correlation at the transition ion site which we have done by applying the LSDA+U method. We show that we have to distinguish two different nearest neighbor exchange integrals for the two systems in question which are all antiferromagnetic with values between -1.0 and -2.0 meV in reasonable agreement with experiment. [arXiv:cond-mat/0511050]