[Zurück]

L.V. Pourovskii, S. Khmelevskyi:
"Quadrupolar superexchange interactions, multipolar order, and magnetic phase transition in UO₂";
Physical Review B, 99 (2019), S. 0944391 - 0944398.

The origin of noncollinear magnetic order in UO2 is studied by an ab initio dynamical-mean-field-theory
framework in conjunction with a linear-response approach for evaluating intersite superexchange interactions
between U 5 f 2 shells. The calculated quadrupole-quadruple superexchange interactions are found to unambiguously
resolve the frustration of face-centered-cubic U sublattice toward stabilization of the experimentally
observed noncollinear 3k-magnetic order. Therefore, the exotic 3k-antiferromagnetic order in UO2 can be
accounted for by a purely electronic exchange mechanism acting in the undistorted cubic lattice structure. The
quadrupolar short-range order above magnetic ordering temperature TN is found to qualitatively differ from the
long-range order below TN .

http://dx.doi.org/10.1103/PhysRevB.99.094439