Nonlinear magnetoelectric effect in paraelectric state of Co4Nb2O9 single crystal

Yiming Cao (1, 2, 3) , Guochu Deng (4) , Přemysl Beran (5) , Zhenjie Feng (6) , Baojuan Kang (6) , Jincang Zhang (6, 7) , Nicolas Guiblin (2) , Brahim Dkhil (2) , Wei Ren (6, 7) , Shixun Cao (6, 7)

1 Center of Magnetic Materials and Devices, Key laboratory for Advanced Functional and Low Dimensional Materials of Yunnan Higher Education Institute
2 SPMS - Laboratoire Structures, Propriétés et Modélisation des solides
3 Shanghai University
4 ANSTO - Australian Nuclear Science and Technology Organisation [Australie]
5 Nuclear Physics Institute CAS
6 Department of Physics, International Center of Quantum and Molecular Structures
7 Shanghai Key Laboratory of hight Temperature Superconductors

We report the structural, magnetoelectric (ME), magnetic and electric control of magnetic properties in Co4Nb2O9 (CNO) single crystal. A detailed ME measurement reveals a nonlinear ME effect instead of a linear ME effect in CNO single crystal. By fitting the magnetization-electric field (M-E) curve, it can be found that the linear (αe) and quadratic (γ) coefficients equal to ~8.27 ps/m and ~−6.46 ps/MV for upper branch, as well as ~8.38 ps/m and ~6.75 ps/MV for the lower branch. More importantly, a pronounced response was observed under a small cooling magnetic field, which cannot even cause the spin flop. This suggests a magnetoelectric effect can occur at paraelectric state for CNO single crystal. Furthermore, we also found that the magnetization of every axis responds to electric field applied along a-axis, but fails to do so when the electric field is applied c-axis. Such findings supply a direct evidence to the magnetic structure and ME coupling mechanism indirectly reflected by our neutron experiment.

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Physique [physics]; Matière Condensée [cond-mat]

Yiming Cao, Guochu Deng, Přemysl Beran, Zhenjie Feng, Baojuan Kang, et al.. Nonlinear magnetoelectric effect in paraelectric state of Co4Nb2O9 single crystal. Scientific Reports, 2017, 7 (1), ⟨10.1038/S41598-017-14169-3⟩. ⟨hal-01781491⟩