| Autor: |
Baral, Raju, Christensen, Jacob, Hamilton, Parker, Ye, Feng, Chesnel, Karine, Sparks, Taylor D., Ward, Rosa, Yan, Jiaqiang, McGuire, Michael A., Manley, Michael E., Staunton, Julie B., Hermann, Raphaël P., Frandsen, Benjamin A. |
| Rok vydání: |
2022 |
| Předmět: |
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| Zdroj: |
Matter, 5, pp. 1853-1864 (2022) |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1016/j.matt.2022.03.011 |
| Popis: |
Short-range magnetic correlations can significantly increase the thermopower of magnetic semiconductors, representing a noteworthy development in the decades-long effort to develop high-performance thermoelectric materials. Here, we reveal the nature of the thermopower-enhancing magnetic correlations in the antiferromagnetic semiconductor MnTe. Using magnetic pair distribution function analysis of neutron scattering data, we obtain a detailed, real-space view of robust, nanometer-scale, antiferromagnetic correlations that persist into the paramagnetic phase above the N\'eel temperature $T_{\mathrm{N}}$ = 307 K. The magnetic correlation length in the paramagnetic state is significantly longer along the crystallographic $c$ axis than within the $ab$ plane, pointing to anisotropic magnetic interactions. Ab initio calculations of the spin-spin correlations using density functional theory in the disordered local moment approach reproduce this result with quantitative accuracy. These findings constitute the first real-space picture of short-range spin correlations in a magnetically enhanced thermoelectric and inform future efforts to optimize thermoelectric performance by magnetic means. |
| Databáze: |
arXiv |
| Externí odkaz: |
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