Large spontaneous exchange bias in a weak ferromagnet Pb6Ni9(TeO6)5

TL;DR

This study reveals that Pb6Ni9(TeO6)5 exhibits a large spontaneous exchange bias and magnetodielectric coupling, making it a rare bulk material with potential for magnetic and electronic applications.

Contribution

It reports the discovery of large spontaneous exchange bias in a new weak ferromagnet without external doping, along with detailed magnetic and dielectric properties.

Findings

Large spontaneous exchange bias of 0.19 T at 2 K

Magnetodielectric coupling observed at TN

High coercive field of 1.32 T at 2 K

Abstract

We report the magnetic and dielectric behavior of Pb6Ni9(TeO6)5, a new compound comprising the honeycomb-like layers of S=1 spins, through detailed structural, magnetic and dielectric investigation. An antiferromagnetic-type transition at 25 K (TN) with weak-ferromagnetic behavior is revealed. Interestingly, a large value of coercive field of 1.32 T at 2 K is observed. The isothermal magnetization after zero-field-cooled condition, it exhibits the presence of large spontaneous exchange bias (SEB) with a magnitude of 0.19 T at 2 K; which is rare in single bulk materials, especially without external doping. The value of |HEB| further enhances to 0.24 T under 16 T field-cooled condition, confirming the presence of large exchange bias in the material. In addition, the dielectric constant shows an anomaly at the onset of TN, indicating the presence of magnetodielectric coupling.