Atomistic structure and energetics of GdN clusters in Gd-doped GaN

Wu M, Erwin SC, Trampert A (2014)

Publication Status: Published

Publication Type: Journal article

Publication year: 2014

Journal

Acta Materialia Elsevier

Publisher: PERGAMON-ELSEVIER SCIENCE LTD

Book Volume: 76

Pages Range: 87-93

DOI: 10.1016/j.actamat.2014.05.009

Abstract

We present a transmission electron microscopy (TEM) and density-functional theory (DFT) study of the structure, formation and energetics of nanoscale clusters of GdN in Gd-doped GaN, a well-known magnetic semiconductor. The atomic configuration of the clusters was determined by comparing displacement maps from high-resolution TEM images to those predicted by atomistic models. We find that the GdN clusters are coherently embedded in the GaN lattice, and have a bilayer platelet shape whose internal crystal structure is slightly distorted rocksalt. The optimum width of the platelet clusters was explored using DFT in conjunction with a Frenkel-Kontorova (FK) model for describing the energetics of embedding. The results predict a platelet width that is reasonably consistent with the size obtained from TEM images. The FK results indicate that the observed platelet size is a compromise between the gain in cohesive energy from forming large GdN clusters and the penalty from interfacial strain energy due to lattice mismatch between the GdN cluster and GaN host. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Authors with CRIS profile

Mingjian Wu Lehrstuhl für Werkstoffwissenschaften (Mikro- und Nanostrukturforschung)

Additional Organisation(s)

Interdisziplinäres Zentrum, Center for Nanoanalysis and Electron Microscopy (CENEM)

Involved external institutions

U.S. Naval Research Laboratory US United States (USA) (US) Paul-Drude-Institut für Festkörperelektronik - Leibniz-Institut im Forschungsverbund Berlin e.V. DE Germany (DE)

How to cite

APA:

Wu, M., Erwin, S.C., & Trampert, A. (2014). Atomistic structure and energetics of GdN clusters in Gd-doped GaN. Acta Materialia, 76, 87-93. https://dx.doi.org/10.1016/j.actamat.2014.05.009

MLA:

Wu, Mingjian, S. C. Erwin, and Achim Trampert. "Atomistic structure and energetics of GdN clusters in Gd-doped GaN." Acta Materialia 76 (2014): 87-93.

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