Magnetic phase diagram of the antiferromagnetic pyrochlore Gd2Ti2O7

TL;DR

This study investigates the magnetic phase diagram of Gd2Ti2O7, revealing strong anisotropic behavior under magnetic fields and highlighting the need for advanced theoretical models beyond mean-field approximations.

Contribution

The paper provides detailed low-temperature phase diagrams of Gd2Ti2O7 for different magnetic field directions, demonstrating complex anisotropic behavior not explained by simple models.

Findings

Strong anisotropic behavior in magnetic response

Phase diagrams constructed for three field directions

Indication that advanced theories are needed beyond mean-field

Abstract

Gd2Ti2O7 is a highly frustrated antiferromagnet on a pyrochlore lattice, where apart from the Heisenberg exchange the spins also interact via dipole-dipole forces. We report on low-temperature specific heat measurements performed on single crystals of Gd2Ti2O7 for three different directions of an applied magnetic field. The measurements reveal the strongly anisotropic behaviour of Gd2Ti2O7 in a magnetic field despite the apparent absence of a significant single-ion anisotropy for Gd3+. The H-T phase diagrams are constructed for H//111], H//[110] and H//[112]. The results indicate that further theoretical work beyond a simple mean-field model is required.