Influence of heating on the measured friction behavior of graphene evaluated under ultra-high vacuum conditions
Bibliographic record
Abstract
Atomic scale friction measurements of exfoliated graphene on a silicon oxide substrate were conducted under ultra-high vacuum (UHV) conditions using an atomic force microscope. Two groups of samples were prepared: one that was heated for 3 h at 800 °C in the UHV chamber and one that was not heated in the UHV chamber. The heated sample showed much lower friction, a lower pull-off force during unloading, and no hysteresis between loading and unloading friction measurements on the heated sample compared with the unheated sample. Additionally, a significantly higher tilt of the friction loop was observed in the unheated sample compared with no or very little tilt of friction loops in the heated sample. Interpretation of lateral forces using the Prandtl–Tomlinson model showed a significantly higher energy corrugation on the unheated sample, but similar lateral contact stiffnesses. Furthermore, no hysteresis in either the energy corrugation or lateral contact stiffness was observed in either sample, suggesting that friction hysteresis is less likely correlated with the energy corrugation and lateral contact stiffness. These observations suggest that surface contamination was present on the unheated sample, which is removed or reduced to undetectable levels on the heated sample. Furthermore, the study distinguishes features in the friction behavior induced by surface contamination with those associated with graphene's intrinsic properties.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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) | 0.000 | 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 teacher head, 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".