Structural, magnetic and dielectric properties of BaFe₂Se₃ crystals

¹ Hefei National Laboratory for Physical Sciences at the Microscale, Department of Physics, and CAS Key Laboratory of Strongly- coupled Quantum Matter Physics, University of Science and Technology of China - Hefei 230026, China
² Department of Physics and Astronomy, University of Tennessee - Knoxville, TN 37996-1200, USA
³ School of Physics and Materials Science, Anhui University - Hefei, Anhui 230601, China
⁴ Collaborative Innovation Center of Advanced Microstructures - Nanjing 210093, China

^(a) yyw@ustc.edu.cn

Received: 22 January 2019
Accepted: 26 April 2019

Abstract

Recently, theoretical studies have indicated that BaFe₂Se₃ may host a ferrielectric polarization and an uncompensated ferroelectricity driven by the exchange striction in its magnetic block order. Here, structural, magnetic, electrical transport, dielectric, and magneto-dielectric properties in the BaFe₂Se₃ single crystals were systematically investigated. Below 320 K, BaFe₂Se₃ is a semiconductor, and the thermal activated transport processes with different activation energies were used to describe the conductivities in high and low temperature ranges. Magnetization measurements show a crossover from a short-range antiferromagnetic correlation to a long-range antiferromagnetic order at around 230 K and another antiferromagnetic transition at 150 K. The dielectric constant can be changed by about 6% in a magnetic field of 8 T. However, the ferrielectric characteristics of BaFe₂Se₃ are difficult to be fully verified by electric polarization and dielectric measurements, which may be related to the quite narrow energy gap and low resistivity.