Effects of Ga doping on the electric and magnetic properties of DyMn1−xGaxO3

Ga³⁺ for Mn³⁺ substitution in multiferroic DyMn_1−xGa_xO₃(x = 0, 0.02, 0.05, 0.1, 0.2, 0.3 and 0.4) has been performed to study the change on Mn³⁺ ordering, which also influences on the ordering of Dy³⁺. The samples are pure and their dielectric constant, electric polarization and magnetic properties have been investigated. When the content of Ga³⁺ increases above 0.1, multiferroic properties completely disappear. These results indicate that Ga³⁺ for Mn³⁺ substitution in DyMnO₃ bulk can reduce the exchange interactions of J_Mn−Mn, J_Dy−Mn and the bond angle of Mn-O-Mn, while the electric polarization is observed to decrease rapidly, even for small Ga doping, and the anomaly at low T in P(T) associated with the Dy ordering is no longer observed for x = 0.05.