Magnetoelectric effect of Cr₂O₃ in strong static magnetic fields

Abstract

The magnetoelectric effect of Cr₂O₃ single crystals has been studied in magnetic fields up to 20 T in the range of liquid helium to room temperature In the antiferromagnetic phase for low magnetic fields the well known results for the magnetoelectric effect below the Néel temperature were reproduced. In the spin-flop phase, for magnetic fields above a critical field (H > H _crit ≃ 10 T), the magnetic field induced electric polarization has been measured along all three crystallographic directions. A magnetoelectric effect, linear in the magnetic field was found for the three orientalions leading to the conclusion that the magnetic ground state symmetry of the spin-flop phase is either 1′ or 2/m′, where 2′/m can be excluded.

Key Words:

• Cr₂O₃
• magnetoelectric effect
• high magnetic fields
• spin-flop phase.