Low-temperature phase transition in ErMn2O5

Abstract
From the measurements of dielectric constant, pyroelectricity, magnetoelectric effect and magnetization, we conclude that ErMn2O5 is ferroelectric below 37 K. In addition, magnetoelectric susceptibility increases remarkably with decreasing temperature below approximately 10 K, accompanied with the growth of magnetic long-range ordering of Er3+. We suppose that this magnetic ordering brings a change in the crystal structure, resulting in the change in spontaneous polarization. A magnetic-field-induced transition occurs between 10 and 30 kOe in this low-temperature phase.