Pressure-induced commensurate order in TbMn 2 O 5 and DyMn 2 O 5 : Influence of rare-earth anisotropy and 3 d − 4 f exchange

M. Deutsch (1, 2) , W. Peng (3) , P. Foury-Leylekian (3) , V. Balédent (3) , S. Chattopadhyay (4) , M. T Fernandez-Diaz (5) , T. C Hansen (5) , A. Forget (6) , D. Colson (6) , M. Greenblatt (7) , M.-B. Lepetit (8, 5) , S. Petit (9, 10) , I. Mirebeau (11, 10)

1 CRM2 - Cristallographie, Résonance Magnétique et Modélisations
2 LLB - UMR 12 - Laboratoire Léon Brillouin
3 LPS - Laboratoire de Physique des Solides
4 HZDR - Helmholtz-Zentrum Dresden-Rossendorf
5 ILL - Institut Laue-Langevin
6 LNO - Laboratoire Nano-Magnétisme et Oxydes
7 Department of Chemistry and Chemical Biology
8 NEEL - TMC - Théorie de la Matière Condensée
9 G3A - Groupe 3 axes
10 NFMQ - LLB - Nouvelles frontières dans les matériaux quantiques
11 GDP - Groupe Diffraction Poudres

The magnetic structure of TbMn 2 O 5 and DyMn 2 O 5 multiferroics has been studied by high-pressure neutron diffraction in a large pressure range up to 6.6 GPa. In both cases, we observe a pressure-induced commensurate magnetic phase with propagation vector (1 2 0 1 2), growing with pressure at the expense of the ambient pressure phases. Being previously observed in YMn 2 O 5 and PrMn 2 O 5 , this phase is most likely a generic feature of the RMn 2 O 5 multiferroic family. A simple model is proposed to explain qualitatively the emergence of this pressure-induced phase. Differences between TbMn 2 O 5 and DyMn 2 O 5 behaviors at ambient and low pressures provide clues on the interaction scheme.

Domaines: Cristallographie; Matière Condensée [cond-mat]

M. Deutsch, W. Peng, P. Foury-Leylekian, V. Balédent, S. Chattopadhyay, et al.. Pressure-induced commensurate order in TbMn 2 O 5 and DyMn 2 O 5 : Influence of rare-earth anisotropy and 3 d − 4 f exchange. Physical Review B, 2018, 98 (2), pp.024408. ⟨10.1103/PhysRevB.98.024408⟩. ⟨hal-01835070⟩