Effects of a weak magnetic surface anisotropy on the magnetic phase diagram of the dipolar antiferromagnetic Heisenberg system
Bibliographic record
Abstract
The results of a series of Monte Carlo simulations are presented which examine the effect of a weak magnetic surface anisotropy on the phase behavior of a system of classical three-dimensional spins on a square lattice. In addition to the magnetic surface anisotropy the spins are assumed to interact through a nearest neighbor antiferromagnetic exchange interaction $(J<0)$ and the long range dipolar interaction. The magnetic phase diagram obtained from these simulations is presented for both a negative (planar) and positive (perpendicular) magnetic surface anisotropy constant. In both cases the $JT$ phase diagram exhibits an in-plane dipolar phase for low values of the exchange constant and a perpendicular antiferromagnetic phase for larger values. Both the location and temperature dependence of the phase boundary separating these two phases is shown to be dependent on the sign of the magnetic surface anisotropy constant. In particular the phase boundary is found to monotonically decrease for a negative surface anisotropy and monotonically increase for a positive value. This implies the existence of a thermally induced reorientation transition in which the sequence of states is determined by the sign of the surface anisotropy constant. The results from these simulations are discussed within the context of previous studies on similar systems.
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 | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| 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".