Regensburg 2022 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 6: Computational Materials Modelling: Defects / Alloys
MM 6.6: Vortrag
Montag, 5. September 2022, 17:15–17:30, H44
Electronic band gap of AlxSc1−xN: a comparison of CPA and SQS — •Jan M. Waack1,2, Markus Kremer1,2, Michael Czerner1,2, and Christian Heiliger1,2 — 1Institut für theoretische Physik, Justus-Liebig-Universität Gießen, Germany — 2Center for Materials Research (LaMa), Justus-Liebig-Universität Gießen, Germany
Calculating physical properties of random substitutional solid solutions such as AlxSc1−xN requires specific methods such as the coherent potential approximation (CPA)[1] and special quasi-random structures (SQS)[2]. We compare the CPA in the framework of the atomic sphere approximation (ASA) Korringa-Kohn-Rostoker (KKR) density functional theory (DFT) with the SQS using the plane-wave pseudopotential DFT to calculate the lattice parameters and electronic band structures of the face-centered cubic phase of AlxSc1−xN (with 0 ≤ x ≤ 1).
Using the low-computational-cost LDA-1/2 quasiparticle method[3] to calculate the electronic band structures within SQS and CPA, we present the first implementation of LDA-1/2 within the KKR DFT. We find that both the lattice parameter and the indirect band gap satisfy Vegard’s law including a bowing parameter.
[1] C. Franz, M. Czerner, and C. Heiliger, Phys. Rev. B 88, 94421 (2013). https://doi.org/10.1103/PhysRevB.88.094421
[2] A. Zunger, S.-H. Wei, L. G. Ferreira, and J. E. Bernard, Phys. Rev. Lett. 65, 353 (1990). https://doi.org/10.1103/PhysRevLett.65.353
[3] L. G. Ferreira, M. Marques, and L. K. Teles, Phys. Rev. B 78, 125116 (2008). https://doi.org/10.1103/PhysRevB.78.125116