Local environment of nitrogen in GaNyAs1−y epilayers on GaAs (0 0 1) studied using X-ray absorption near edge spectroscopy
| Autor: | J.J. Rehr, M. Prange, M.W.C. Dharma-wardana, J.A. Gupta, E.D. Crozier, A. Jürgensen |
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| Rok vydání: | 2005 |
| Předmět: |
Condensed Matter - Materials Science
Chemistry Alloy Analytical chemistry X-ray Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences 02 engineering and technology General Chemistry engineering.material 021001 nanoscience & nanotechnology Condensed Matter Physics Epitaxy Threshold energy 01 natural sciences XANES Condensed Matter::Materials Science 0103 physical sciences Materials Chemistry engineering 010306 general physics 0210 nano-technology Polarization (electrochemistry) Spectroscopy Absorption (electromagnetic radiation) |
| Popis: | X-ray absorption near-edge spectroscopy (XANES) is used to study the N environment in bulk GaN and in GaN{y}As{1-y} epilayers on GaAs (001), for y \~5%. Density-functional optimized structures were used to predict XANES via multiple-scattering theory. We obtain striking agreement for pure GaN. An alloy model with nitrogen pairs on Ga accurately predicts the threshold energy, the width of the XANES ``white line'', and features above threshold, for the given X-ray polarization. The presence of N-pairs may point to a role for molecular N_2 in epitaxial growth kinetics. Four pages (PRL style) with two figures |
| Databáze: | OpenAIRE |
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