Probing magnetic symmetry in antiferromagnetic Fe4Nb2O9 single crystals by linear magnetoelectric tensor

TL;DR

This study investigates the magnetoelectric properties of Fe4Nb2O9 single crystals, revealing significant effects near 95 K and establishing a comprehensive linear ME tensor consistent with a low magnetic symmetry group.

Contribution

It provides the first detailed experimental analysis of the linear magnetoelectric tensor in Fe4Nb2O9, linking magnetic symmetry to observed ME effects.

Findings

Significant magnetodielectric effects near 95 K in specific crystallographic directions.

Induced polarization up to 100 μC/m² under magnetic fields up to 9 T.

All nine components of the linear ME tensor are nonzero, indicating low magnetic symmetry.

Abstract

In the present study, we investigated magnetodielectric, magnetoelectric (ME), and angular-dependent polarization in single-crystal Fe4Nb2O9. The magnetodielectric effects in epsilon(x) (x//[100]), epsilon(y) (y//[120]), and epsilon(z) (z//[001]) are found to be significant only around T-N approximate to 95 K when magnetic fields are applied along three orthogonal x-, y- (y//[120]), and z directions. The finite polarization P-x, P-y, and P-z of 70, 100, and 30 mu C/m(2), respectively, can be induced in the antiferromagnetic phase when a finite magnetic field up to 9 T is applied along the three orthogonal directions. The angular-dependent polarization measurements verify the dominating linear ME effects below T-N. From the above experimental results, a linear ME tensor a(ij) with all nine nonzero components can be inferred, demonstrating a much lower magnetic point group of -1' for the canted antiferromagnetic configuration.