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arXiv · 1804.08605

Frustrated Magnetism in Mott Insulating (V$_{1-x}$Cr$_x$)$_2$O$_3$

J. C. Leiner·H. O. Jeschke·R. Valenti·S. Zhang·A. T. Savici·J. Y. Y. Lin·M. B. Stone·M. D. Lumsden·Jiawang Hong·O. Delaire·Wei Bao·C. L. Broholm
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Abstract

V2O3 famously features all four combinations of paramagnetic vs antiferromagnetic, and metallic vs insulating states of matter in response to %-level doping, pressure in the GPa range, and temperature below 300 K. Using time-of-flight neutron spectroscopy combined with density functional theory calculations of magnetic interactions, we have mapped and analyzed the inelastic magnetic neutron scattering cross section over a wide range of energy and momentum transfer in the chromium stabilized antiferromagnetic and paramagnetic insulating phases (AFI & PI). Our results reveal an important magnetic frustration and degeneracy of the PI phase which is relieved by the rhombohedral to monoclinic transition at $T_N=185$ K due to a significant magneto-elastic coupling. This leads to the recognition that magnetic frustration is an inherent property of the paramagnetic phase in $\rm (V_{1-x}Cr_x)_2O_3$ and plays a key role in suppressing the magnetic long range ordering temperature and exposing a large phase space for the paramagnetic Mott metal-insulator transition to occur.

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J. C. Leiner, H. O. Jeschke, R. Valenti, S. Zhang, A. T. Savici, J. Y. Y. Lin, M. B. Stone, M. D. Lumsden, Jiawang Hong, O. Delaire, Wei Bao, C. L. Broholm. 2019-02-22. Frustrated Magnetism in Mott Insulating (V$_{1-x}$Cr$_x$)$_2$O$_3$. https://doi.org/10.1103/physrevx.9.011035

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