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HL: Fachverband Halbleiterphysik

HL 37: Oxide Semiconductors

HL 37.11: Talk

Thursday, March 15, 2018, 12:15–12:30, EW 203

Defect induced magnetism and polaronic states in ZnO — Sanjeev K. Nayak¹, •Waheed A. Adeagbo², Martin Hoffmann³, Matthias Geilhufe⁴, Hichem Ben Hamed², Arthur Ernst^3,5, and Wolfram Hergert² — ¹Department of Materials Science & Engineering, University of Connecticut, USA — ²Institute of Physics, Martin Luther University Halle-Wittenberg, Germany — ³Institute for Theoretical Physics, Johannes Kepler University Linz, Austria — ⁴Nordita, Center for Quantum Materials, KTH Royal Institute of Technology and Stockholm University, Sweden — ⁵Max Planck Institute of Microstructure Physics, Halle, Germany

Crucial issue on magnetism in ZnO in scientific literature with transition metal doped ZnO has been to identify the mechanism for magnetic interaction. However, recent reports on ferromagnetism in pure defected ZnO and Li doped ZnO have brought back our attention to examine the electronic structure of doped ZnO more carefully in order to justify the origin of magnetic moment in p-orbital system. Present understanding goes in the line that localization of holes created from some point defects, such, as Zn-vacancy V_Zn, is responsible for the magnetic moment. The question about the interpretation of first-principles calculations for such a problem is the interest of the present work. We propose that the hole localization in V_Zn, could be achieved by treating the V_Zn−O₄, as a single complex unit of point defect, where the four O are treated separately through a Hubbard-U correction. The treatment gives identical results as in hybrid-functional treatment and non-local external potential functional and is more intuitive.