Report
Magnetic pyroxenes LiCrGe2O6 and LiCrSi2O6: dimensionality crossover in a non-frustrated S=3/2 Heisenberg model
| العنوان: | Magnetic pyroxenes LiCrGe2O6 and LiCrSi2O6: dimensionality crossover in a non-frustrated S=3/2 Heisenberg model |
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| المؤلفون: | Janson, O., Nénert, G., Isobe, M., Skourski, Y., Ueda, Y., Rosner, H., Tsirlin, A. A. |
| سنة النشر: | 2014 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Materials Science |
| الوصف: | The magnetism of magnetoelectric $S$ = 3/2 pyroxenes LiCrSi$_2$O$_6$ and LiCrGe$_2$O$_6$ is studied by density functional theory (DFT) calculations, quantum Monte Carlo (QMC) simulations, neutron diffraction, as well as low-field and high-field magnetization measurements. In contrast with earlier reports, we find that the two compounds feature remarkably different, albeit non-frustrated magnetic models. In LiCrSi$_2$O$_6$, two relevant exchange integrals, $J_1 \simeq$ 9 K along the structural chains and $J_{\text{ic1}}$ $\simeq$ 2 K between the chains, form a 2D anisotropic honeycomb lattice. In contrast, the spin model of LiCrGe$_2$O$_6$ is constituted of three different exchange couplings. Surprisingly, the leading exchange $J_{\text{ic1}}$ $\simeq$ 2.3 K operates between the chains, while $J_1$ $\simeq$ 1.2 K is about two times smaller. The additional interlayer coupling $J_{\text{ic2}}$ $\simeq$ $J_1$ renders this model 3D. QMC simulations reveal excellent agreement between our magnetic models and the available experimental data. Underlying mechanisms of the exchange couplings, magnetostructural correlations, as well as implications for other pyroxene systems are discussed. Comment: 11 pages, 8 figures, 3 tables + Supplementary information |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1103/PhysRevB.90.214424 |
| URL الوصول: | http://arxiv.org/abs/1402.5054 |
| رقم الانضمام: | edsarx.1402.5054 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1103/PhysRevB.90.214424 |
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