Intrinsic Structural Disorder and the Magnetic Ground State in Bulk EuTiO3:
In this work we studied the magnetic properties of single-crystal magnetoelectric EuTiO3. The results indicate the presence of nanoscale disorder below the cubic-tetragonal phase transition of this material. We demonstrate that electric fi eld cooling acts to restore monocrystallinity, thus con firming that emergent structural disorder is an intrinsic low-temperature property of EuTiO3. Using torque magnetometry, we deduce that tetragonal EuTiO3 enters an easy-axis antiferromagnetic phase at 5.6 K, with a first-order transition to an easy-plane ground state below 3 K. Our data is reproduced by a 3D anisotropic Heisenberg spin model.
