When Does a Glass Transition Temperature Not Signify a Glass Transition?
Bibliographic record
Abstract
We present a simple model that links enhanced mobility at the free surface to the dilatometric glass transition temperature, T g in thin films. The model shows that what is typically measured as a dilatometric T g, characterized by the hallmark “kink” in the plot of film thickness versus temperature, only represents the dynamics of an infinitesimally thin layer of the sample. In other words, the measured dilatometric T g value in thin films is no longer a good reporter of the dynamics. Calculations based on the model are found to agree with a vast body of thin film T g measurements. While mathematically simple, the model contains all the necessary physics of a near surface layer with enhanced dynamics and a length scale over which the surface dynamics monotonically varies from surface enhanced to bulk-like. The model demonstrates that the typical dilatometric measurement of the glass transition is not necessarily a real glass transition.
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 | 0.004 | 0.023 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.012 |
| Scholarly communication | 0.003 | 0.011 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.006 | 0.005 |
| Insufficient payload (model declined to judge) | 0.003 | 0.002 |
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".