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 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 | 0.009 | 0.007 |
| Meta-epidemiology (narrow) | 0.006 | 0.010 |
| Meta-epidemiology (broad) | 0.002 | 0.011 |
| Bibliometrics | 0.003 | 0.008 |
| Science and technology studies | 0.008 | 0.010 |
| Scholarly communication | 0.007 | 0.008 |
| Open science | 0.012 | 0.012 |
| Research integrity | 0.009 | 0.010 |
| Insufficient payload (model declined to judge) | 0.407 | 0.008 |
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".