Numerical characterization of the Ga interstitial self-diffusion mechanisms in GaAs
Bibliographic record
Abstract
Recent diffusion experiments by Bracht and Brotzmann [H. Bracht and S. Brotzmann, Phys. Rev. B 71, 115216 (2005)] show that the dominant charge states for GaI diffusion in GaAs should be 0 and +1 with surprisingly high enthalpy barriers of 5.45±0.12 and 5.80±0.32 eV, respectively. Using the activation-relaxation technique, coupled with the ab initio code SIESTA, we identify possible migration pathways and barriers for these two charge states. In the +1 charge state, we observe two different migration paths between tetrahedral sites surrounded by Ga atoms (tetra[Ga−Ga]), implicating either a tetrahedral interstitial surrounded by As atoms (tetra[Ga−As]) or a ⟨111⟩-oriented split configuration, with total barriers of 1.4 and 1.3 eV, respectively. Including formation energy, the enthalpy barriers that we find are lower than the experimentally derived values. We analyze the possible causes and the significance of this discrepancy and offer a partial explanation based on the correction method used for finite-size effects.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".