Magnetic-field-induced transition of thulium manganese oxide TmMn₂O₅

Abstract

We report the magnetic field dependence of dielectric constant and magnetoelectric effect of TmMn₂O₅ and YbMn₂O₅ single crystals. An anomalous change of magnetoelectric effect occurs at 5 kOe (TmMn₂O₅) or at 18 kOe (YbMn₂O₅) at 4.2 K, when an magnetic field is applied along the c-direction. The anomaly in YbMn₂O₅ is attributed to a transition between different magnetic structures. In TmMn₂O₅ an anomaly was also observed in dielectric constant. We propose a structural transition caused by a magnetic field.

Key Words:

• Dielectric constant
• spontaneous polarization
• magnetic ordering
• magnetoelectric effect
• magnetic transition
• structural transition
• rare earth manganese oxide
• TmMn₂O₅
• YbMn₂O₅