Oxygen‐Vacancy‐Driven Persistent Luminescence in Mn <sup>2+</sup> ‐Doped MgGeO <sub>3</sub> : Insights from X‐Ray Absorption Fine Structure Spectroscopy
Bibliographic record
Abstract
Mn 2+ ‐doped MgGeO 3 (MMGO) is a near‐infrared‐emitting persistent luminescence (PersL) phosphor. Its low luminescence decay has been linked to vacancies within the MgGeO 3 host, likely associated with Ge, although no direct correlations have been confirmed. In this study, the Ge K‐edge X‐ray absorption fine structure (XAFS) spectroscopy is employed to investigate a series of MMGO submicron‐sized particles with varying afterglow durations. These samples are synthesized using a recently developed hydrothermal method, where it is found that the PersL duration is related to the annealing temperature and the presence of codopants. It is first demonstrated that the XAFS spectra obtained using an in‐house XAFS spectrometer are comparable in quality to those acquired at synchrotron facilities. Analysis of the local Ge environment of the MMGO shows that the PersL duration is directly related to the Ge–O coordination number. Additionally, the introduction of Li + extends the PersL duration of MMGO but does not alter the Ge–O coordination. The findings provide insights into the structural mechanisms driving luminescence and highlight the capability of in‐house XAFS systems to deliver high‐quality data for advanced materials research.
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) | 0.000 | 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 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".