V2O3 famously features all four combinations of paramagnetic versus antiferromagnetic and metallic
versus insulating states of matter in response to percent-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. Our results reveal an important magnetic frustration
and degeneracy of the paramagnetic insulating phase which is relieved by the rhombohedral-to-monoclinic
transition at TN ¼ 185 K. This leads to the recognition that magnetic frustration is an inherent property of
the paramagnetic phase in ðV1−xCrxÞ
2O3 and plays a key role in suppressing the magnetic long-rangeordering
temperature and exposing a large phase space for the paramagnetic Mott metal-insulator transition to occur. c.Published by the American Physical Society