Multiferroic Properties of Single-crystal Dy(Mn,Ga)(2)O-5

Abstract

We have studied flux-grown single crystals of Dy(Mn,Ga)(2)O-5 to find the effects of Ga3+ substitution for Mn3+ in DyMn2O5 on its multiferroic characteristics. Both antiferromagnetic (T-N) and ferroelectric (T-C) transitions were observed in our disordered multiferroic system: a randomly distributed Ga3+ in the square pyramidal site of manganese of the orthorhombic DyMn2O5. At low temperatures below T-N, the metamagnetic transition, a peculiar magnetic behavior observed only in Dy compounds Of RMn2O5, disappeared in Dy(Mn,Ga)(2)O-5. From this observation, we propose that exchange interactions between rare-earth and manganese ions are responsible for the unique metamagnetic transition in DyMn2O5. Ferroelectric polarizations from measurements of the pyro-electric currents also showed an unusual sensitivity to the magnetic field applied during the poling process.