Magnetic Field Effect and Dielectric Anomalies at the Spin Reorientation Phase Transition of GdFe3(BO3)4

TL;DR

This study investigates the spin reorientation phase transition in GdFe3(BO3)4, revealing dielectric anomalies, a first-order transition, and magneto-dielectric effects under magnetic fields, contributing to understanding magnetic and dielectric coupling in this material.

Contribution

The paper provides detailed analysis of the first-order spin reorientation transition and its dielectric and magneto-dielectric effects in GdFe3(BO3)4 under external magnetic fields.

Findings

Dielectric anomalies at T_SR = 9 K separate under magnetic fields.

First-order nature of the spin reorientation transition confirmed.

Magneto-dielectric effect of up to 1% observed at 8 K and 7 kOe.

Abstract

GdFe3(BO3)4 exhibits a structural phase transition at 156 K, antiferromagnetic order of the Fe3+ moments at 36 K followed by a spin reorientation phase transition at 9 K. The reorientation phase transition is studied through dielectric, magnetic and heat capacity measurements under the application of external magnetic fields of up to 7 kOe. The dielectric constant indicates the existence of two distinct anomalies at T_SR = 9 K that separate in temperature under external magnetic fields. The spin rotation phase transition is proven to be of the first-order nature through the magnetic analogue of the Clausius-Clapeyron equation. Magneto-dielectric effect of up to 1% is observed at 8 K and 7 kOe. The uniaxial magnetocaloric effect along the c axis is observed below the spin reorientation phase transition of 9 K.