Piezomagnetism and magnetoelastic memory in uranium dioxide

M Jaime; A Saul; M Salamon; V S Zapf; N Harrison; T Durakiewicz; J C Lashley; D A Andersson; C R Stanek; J L Smith; K Gofryk

doi:10.1038/s41467-017-00096-4

Piezomagnetism and magnetoelastic memory in uranium dioxide

Nat Commun. 2017 Jul 24;8(1):99. doi: 10.1038/s41467-017-00096-4.

Authors

M Jaime¹, A Saul², M Salamon³, V S Zapf³, N Harrison³, T Durakiewicz^{3

4}, J C Lashley⁵, D A Andersson⁶, C R Stanek⁶, J L Smith⁷, K Gofryk⁸

Affiliations

¹ MPA-CMMS, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA. mjaime@lanl.gov.
² Aix-Marseille University, CINaM-CNRS UMR 7325 Campus de Luminy, Marseille cedex 9, 13288, France. saul@cinam.univ-mrs.fr.
³ MPA-CMMS, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
⁴ Institute of Physics, Maria Curie-Sklodowska University, PL-20-031, Lublin, Poland.
⁵ MPA-11, Institute for Materials Science, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
⁶ MST-8, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
⁷ Sigma Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
⁸ Idaho National Laboratory, Idaho Falls, ID, 83415, USA. krzysztof.gofryk@inl.gov.

Abstract

The thermal and magnetic properties of uranium dioxide, a prime nuclear fuel and thoroughly studied actinide material, remain a long standing puzzle, a result of strong coupling between magnetism and lattice vibrations. The magnetic state of this cubic material is characterized by a 3-k non-collinear antiferromagnetic structure and multidomain Jahn-Teller distortions, likely related to its anisotropic thermal properties. Here we show that single crystals of uranium dioxide subjected to strong magnetic fields along threefold axes in the magnetic state exhibit the abrupt appearance of positive linear magnetostriction, leading to a trigonal distortion. Upon reversal of the field the linear term also reverses sign, a hallmark of piezomagnetism. A switching phenomenon occurs at ±18 T, which persists during subsequent field reversals, demonstrating a robust magneto-elastic memory that makes uranium dioxide the hardest piezomagnet known. A model including a strong magnetic anisotropy, elastic, Zeeman, Heisenberg exchange, and magnetoelastic contributions to the total energy is proposed.The nuclear fuel uranium dioxide is of intrinsic interest due to its industrial applications but it also exhibits intriguing electronic and magnetic properties. Here, the authors demonstrate how its complex magnetic structure and interactions give rise to a strong piezomagnetic effect.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.