Effect of B-site Al-doping on electric polarization in DyMnO3

We investigate the effect of Al-doping on the multiferroicity of DyMn1-xAlxO3. It is indicated that a slight doping (0.005 <= x <= 0.01) can significantly enhance the electric polarization which will be suppressed as x>0.03. The possible mechanism for the polarization enhancement is the rearrangement of the Mn spiral spin order upon the Al-doping. Our work demonstrates that the ferroelectricity of DyMnO3 is sensitive to the B-site nonmagnetic doping, allowing an unusual enhancement of the electric polarization. (C) 2010 American Institute of Physics. [doi:10.1063/1.3453869]