New Soft Chemical Routes to Ferroelectric SrBi<sub>2</sub>Ta<sub>2</sub>O<sub>9</sub>
Bibliographic record
Abstract
Ferroelectric ceramics of strontium bismuth tantalate, SrBi 2 Ta 2 O 9 (SBT), have been synthesized in pure layer-structured perovskite phase by two new soft chemical techniques, namely, a sol−gel process and a coprecipitation method. The sol−gel process utilizes ethylene glycol as solvent while the coprecipitation technique makes use of a poly(ethylene glycol) 200 (PEG) and methanol mixture as solvent. The microstructure and properties of the ceramics have been studied and discussed. The sol−gel-derived ceramics sintered at 1200 °C for 8 h show good dielectric and ferroelectric properties with a relative density of 96%, a dielectric constant ε‘ = 227, a remnant polarization P r = 7.6 μC/cm 2 at room temperature, and a maximum dielectric constant ε‘ max = 950 at the Curie temperature T C = 330 °C. In comparison, the SBT ceramics prepared using the coprecipitation method and sintered under the same conditions show a platelike microstructure with preferential grain orientation along the [00 10 ] direction, a relative density of 85%, an ε‘ of 235, a P r of 3.7 μC/cm 2 at room temperature, and an ε‘ max of 850 at T C = 330 °C. The sol−gel-derived ceramics show superior dielectric and ferroelectric properties than the ceramics prepared by the solid-state reactions (ε‘ max ≈ 500 and P r = 4.5 μC/cm 2 ), which can be attributed to a denser and more homogeneous microstructure with a better distribution of grain orientations, thus reducing the preferential grain orientation along the nonpolar c -axis.
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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 | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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; both teacher heads agree on what is shown here.
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".