Anisotropic phonon thermal transport in nitrophosphorene monolayer
Bibliographic record
Abstract
Recent studies have shown that although black phosphorene ($\ensuremath{\alpha}$-P) has promising electrical, thermal, and mechanical properties, its poor stability in the air makes its applications challenging. Very recently, monolayer puckered-phase nitrophosphorene ($\ensuremath{\alpha}$-NP) has emerged as a new two-dimensional material with improved stability compared to $\ensuremath{\alpha}$-P, while it preserves the appealing electronic and mechanical properties of $\ensuremath{\alpha}$-P. However, the phonon transport properties of $\ensuremath{\alpha}$-NP remain poorly understood. In this study, we systematically compare phonon transport and thermal conductivity of $\ensuremath{\alpha}$-NP and $\ensuremath{\alpha}$-P by means of an iterative solution for the Boltzmann transport equation and first-principles calculations. We pay particular attention to careful enforcement of the Born-Huang sum rules on the interatomic force constants so that the flexural phonon branch of $\ensuremath{\alpha}$-NP becomes perfectly quadratic close to the center of the Brillouin zone. We find that $\ensuremath{\alpha}$-NP has a less anisotropic thermal conductivity compared to $\ensuremath{\alpha}$-P, with the room-temperature values of 37.65 and $18.66\phantom{\rule{4pt}{0ex}}{\mathrm{W}\phantom{\rule{0.16em}{0ex}}\mathrm{m}}^{\ensuremath{-}1}\phantom{\rule{0.16em}{0ex}}{\mathrm{K}}^{\ensuremath{-}1}$ in the armchair and zigzag directions, respectively. Interestingly, the anisotropy in the thermal conductivity of $\ensuremath{\alpha}$-NP is found to be reversed compared to that of $\ensuremath{\alpha}$-P, which has a higher thermal conductivity in the zigzag direction than the armchair direction. We found that as opposed to the usual understanding, considering only the directional dependence of the phonon group velocity fails to explain this reversed anisotropic thermal conductivity, and other phonon behaviors, such as avoided crossing of the acoustic and optical phonon branches, play a key role in determining the phonon relaxation time and thermal conductivity in $\ensuremath{\alpha}$-NP. Our results may provide theoretical guidance for future fundamental studies on the anisotropic phonon thermal transport in low-dimensional materials, and they may also enable efficient heat management of nanoelectronic devices based on $\ensuremath{\alpha}$-NP.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 |
| 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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".