Spin gaps in the ordered states of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>La</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:mi>Li</mml:mi><mml:mi>X</mml:mi><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mn>6</mml:mn></mml:msub><mml:mspace width="0.28em"/><mml:mrow><mml:mo>(</mml:mo><mml:mi>X</mml:mi><mml:mo>=</mml:mo><mml:mi>Ru</mml:mi><mml:mo>,</mml:mo><mml:mi>Os</mml:mi><mml:mo>)</mml:mo></mml:mrow></mml:mrow></mml:math> and their relation to the distortion of the cubic double perovskite structure in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>4</mml:mn><mml:msup><mml:mi>d</mml:mi><mml:mn>3</mml:mn></mml:msup></mml:mrow></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>5</mml:mn><mml:msup><mml:mi>d</mml:mi><mml:mn>3</mml:mn></mml:msup></mml:mrow></mml:math> magnets
Bibliographic record
Abstract
Time-of-flight inelastic neutron scattering measurements have been carried out on polycrystalline samples of the $4{d}^{3}$ and $5{d}^{3}$ double pervoskite antiferromagnets ${\mathrm{La}}_{2}{\mathrm{LiRuO}}_{6}$ and ${\mathrm{La}}_{2}{\mathrm{LiOsO}}_{6}$. These reveal the development of an inelastic spin gap in ${\mathrm{La}}_{2}{\mathrm{LiRuO}}_{6}$ and ${\mathrm{La}}_{2}{\mathrm{LiOsO}}_{6}$ of $\ensuremath{\sim}1.8(8)$ and 6(1) meV, below their respective ordering temperatures ${T}_{N},\phantom{\rule{0.28em}{0ex}}\ensuremath{\sim}23.8$ and 30 K. The bandwidths of the spin excitations are shown to be $\ensuremath{\sim}5.7(9)\phantom{\rule{0.28em}{0ex}}\text{and}\phantom{\rule{0.28em}{0ex}}12(1)\phantom{\rule{0.28em}{0ex}}\mathrm{meV}$, respectively, at low temperatures. Spin gaps are surprising in such magnets as the ${t}_{2g}$ levels of ${\mathrm{Ru}}^{5+}$ or ${\mathrm{Os}}^{5+}$ are expected to be half-filled, resulting in an anticipated orbital singlet for both materials. We compare these results in monoclinic double perovskites ${\mathrm{La}}_{2}{\mathrm{LiRuO}}_{6}$ and ${\mathrm{La}}_{2}{\mathrm{LiOsO}}_{6}$ with those in cubic ${\mathrm{Ba}}_{2}{\mathrm{YRuO}}_{6}$ and ${\mathrm{Ba}}_{2}{\mathrm{YOsO}}_{6}$ as well as with those in other monoclinic ${\mathrm{La}}_{2}{\mathrm{NaRuO}}_{6},\phantom{\rule{0.28em}{0ex}}{\mathrm{La}}_{2}{\mathrm{NaOsO}}_{6}$, and ${\mathrm{Sr}}_{2}{\mathrm{ScOsO}}_{6}$ and model the inelastic magnetic scattering with linear spin-wave theory using minimal anisotropic exchange interactions. We discuss the possible role of the distortion of the face-centered-cubic double perovskite structure on the spin gap formation and geometric frustration in these materials and show that ${T}_{N}$ scales with the top of the spin-wave band in all members of these families that display long-range order.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.015 | 0.001 |
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".