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.

Key Words:

• Ferroelectric transition
• spontaneous polarization
• magnetic ordering
• helimagnetic ordering
• magnetoelectric effect
• rare earth
• ErMn₂O₅