Coexistence of a- and c-axis polarization and independent rare earth ordering induced polarization in Gd0.5Dy0.5MnO3

Orateur : A. SUNDARESAN

Magnetoelectric measurements on a single crystal of orthorhombic manganite, Gd0.5Dy0.5MnO3 reveal that the ferroelectric polarization exists along the a-axis with a significant polarization along the c-axis as well. Unlike RMnO3 (R=Tb and Dy), this system exhibits a flop of ferroelectric polarization from a to c axis when magnetic field is applied along a-axis (H ǁa). Intriguingly, there is a large enhancement of Curie temperature and ferroelectric polarization along the a-axis (Pa) when the magnetic field is applied along the b-axis (H ǁb). Further, below TNR = 6 K, the polarization along the a-axis decreases to almost zero indicating that the magnetic ordering of R-ions destroy the polarization due to cycloidal spins of Mn ions. At the same time, the rare earth ordering induces polarization independently. In my talk, I shall compare and contrast these results with the other RMnO3 systems.

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