Ho substitution suppresses collinear Dy spin order and enhances polarization in DyMnO3

The multiferroic behaviors of Dy1-xHoxMnO3 are investigated in order to reveal the effects of Ho-substitution on the independent collinear Dy spin order and ferroelectric polarization at low temperature. It is demonstrated that a partial Ho-substitution of Dy ions significantly suppresses the independent Dy spin order at low temperature on one hand, and maintains the R-Mn spin coupling on the other hand, thus leading to a remarkable enhancement of the polarization at low temperature. (C) 2011 American Institute of Physics. [doi:10.1063/1.3636399]