Tuneable blue-green co-activated CaAl2O4: 0.1 mol% Tb3+, x mol% Sm3+ (0 ≤ x ≤ 2) nanophosphor prepared by citrate sol-gel method
Bibliographic record
Abstract
This study reports the analysis of tuneable blue-green phosphor of calcium aluminate (CaAl2O4) co-doped with terbium (Tb3+) and varying concentration of samarium (Sm3+) (0 ≤ x ≤ 2). The powder samples were synthesized by using the citrate sol-gel method and annealed at 900 °C for 2 h (h) for all samples. The X-ray powder diffraction (XRD) results revealed a developing amorphous monoclinic structure of CaAl2O4. Co-doping with Tb3+ and Sm3+ slightly affected the structure of synthesized CaAl2O4. Scanning electron microscope (SEM) results showed that co-doping the host material of CaAl2O4 slightly affected the morphology of the synthesized nanopowders. The transition electron microscope (TEM) images showed that the particle sizes of the host material were affected by doping. Ultraviolet–visible (UV–Vis) reflection spectroscopy suggested that the band gap of co-doped CaAl2O4:0.1 mol% Tb3+, x% Sm3+ (0 ≤ x ≤ 2) ranges between 5.05 and 5.20 eV. The photoluminescence (PL) results showed several emission peaks located at 420, 440, 484, 548, 558, 562, 584, 603 and 654 nm. Emission peaks at 420, 440, 484 and 558 nm were attributed to the host material. The peaks at 548 and 558 nm are originating from 5D4→7F6 and 5D4→7F5 transitions of Tb3+ while the peaks at 562, 603 and 654 nm seems to be originating from the dopant of Sm3+ which may be assigned to 4G5/2 → 6H5/2, 4G5/2 → 6H7/2, and 4G5/2 → 6H9/2 transitions of Sm3+, respectively. CIE coordinates results suggested that the emission colour can be tuned from bluish to greenish as x% Sm3+ concentration is varied.
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) | 0.001 | 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".