The origin of multiple magnetic and dielectric anomalies of Mn-doped DyMnO3 in low temperature region

Abstract

The solid solution (Dy1−xMnx)MnO3−δ (0.037 ≤ x ≤ 0.142) has been synthesized by the conventional solid-state method. Powder X-ray diffraction and selected area electron diffraction reveal that all the samples crystallize in the space group Pnma. The magnetic and dielectric studies on Mn-doped DyMnO3 reveal existence of three anomaly behaviors in low temperature region. A transition from an incommensurate antiferromagnetic ordering of Mn3+ spins at T1 ∼ 37 K, a lock-in transition at TC1 ∼ 18 K. The second antiferromagnetic transition at T2 ∼ 7 K, originating from the ordering of Dy moments with a slight Mn doping range of 0.037 ≤ x < 0.087, and it disappears with 0.087 ≤ x ≤ 0.142 due to damage of the Dy spin ordering. Interestingly, the Mn doping in DyMnO3 suppresses the ferroelectric ordering, resulting in reduction in ferroelectric ordering temperatures, whereas an increase in antiferromagnetic transition temperatures has been observed.