Magnetodielectric Relaxation in Ho 2 Ti 2 O 7 and Dy 2 Ti 2 O 7 Spin Ice

Materials having magnetoelectricity is one of the highest priority research topics for the development of novel multifunctional materials. Recently, Ho2Ti2O7 and Dy2Ti2O7 pyrochlores show the coexistence of ferroelectricity with complex magnetism. The present study shows that these spin ices show an anomalous nature of relaxation taking place at ~ 4 K. Arrhenius nature of frequency dispersion behavior and order of characteristic relaxation time τ0 suggest that observed relaxation is associated with non-interacting electric dipoles induced by lattice distortions. These lattice distortions are associated with prevailing 3in-1out spin structure via magnetostriction mechanism, thus enabling the control of ferroelectricity though magnetism.