Field-driven magnetostructural transitions in GeCo 2 O 4

Xavier Fabrèges (1, 2) , E. Ressouche (3) , F. Duc (1) , S. de Brion (4) , Mehdi Amara (4) , C. Detlefs (5) , L. Paolasini (5) , E. Suard (6) , L.-P. Regnault (3) , Benjamin Canals (7) , P. Strobel (8) , Virginie Simonet (4)

1 LNCMI-T - Laboratoire national des champs magnétiques intenses - Toulouse
2 LLB - UMR 12 - Laboratoire Léon Brillouin
3 CEA - Commissariat à l'énergie atomique et aux énergies alternatives
4 NEEL - MagSup - Magnétisme et Supraconductivité
5 ESRF - European Synchrotron Radiation Facility
6 ILL - Institut Laue-Langevin
7 NEEL - TMC - Théorie de la Matière Condensée
8 NEEL - MRS - Matériaux, Rayonnements, Structure

In the spinel compound GeCo2O4, the Co2+ pyrochlore sublattice presents remarkable magnetic eld-induced behaviors that we unveil through neutron and X-ray single-crystal diffraction. The Néel ordered magnetic phase is entered through a structural lowering of the cubic symmetry. In this phase, when a magnetic field is applied along a 2-fold cubic direction, a spin-op transition of one fourth of the magnetic moments releases the magnetic frustration and triggers magnetostructural effects. At high field, these ultimately lead to an unusual spin reorientation associated with structural changes.

Mots clés: numbers: 7525-j; 7550Ee; 7530Gw; 7580+q

Domaines: Electrons fortement corrélés [cond-mat.str-el]

Xavier Fabrèges, E. Ressouche, F. Duc, S. de Brion, Mehdi Amara, et al.. Field-driven magnetostructural transitions in GeCo 2 O 4. Physical Review B, 2017, 95 (1), pp.014428. ⟨10.1103/PhysRevB.95.014428⟩. ⟨hal-01632250⟩