Mn,Cu Doped Dy MnO₃: Synthesis,Structure,Magnetic And Dielectric Property

Multiferroics are materials in which can simultaneously show two or more primary ferroic properties?ferromagnetism,ferroelectricity,and ferroelasticity?in single phase in certain temperature range.At present,these materials with the coexistence of ferroelectric order and ferromagnetic or antiferromagnetic order also show magneto-electric effect which has great potential application in the areas of information storage.The perovskite manganese oxides are very important and widely studied multiferroics,and the stoichiometric ratio of these compounds has an extremely important effect on the crystal structure and physical properties.They show great tolerance for A-and B-?Mn?site ions radius and valence state,which helps us to doping materials modified.In view of the above characteristics,doping modification has become an important method to study these compounds,that is,the substitution of different elements in the A-and Mn-sites in the perovskite manganese oxides.TbMnO₃ as an example of Rare earth manganates is typical multiferroics compounds that have been extensively studied.DyMnO₃ is kind of typical orthorhombic pervoskite that is similar to TbMnO₃,which has a phase transition at about 39K,but few studies have been reported on its multiferroics.In this work,we try to investigate the multiferroics of DyMnO₃ system by studying the effect of A-and B-site ions doping on its structure and properties.In this work,the solid solution of DyMnO₃ doped with Mn and Cu was synthesized through the traditional solid-state reaction.The structure,magnetic properties and dielectric properties were studied.The main results as follows:1.DyMnO₃ doped with Mn ions at A-site,to form Dy_1-xMn_xMnO_3-?solid solution,the solid solubility range of 0.024-0.142.The crystal structure of the solid solution does not change due to the doping of Mn,and the space group is Pnma as well.The a and c lattice parameter decrease with the increase of Mn content,and b lattice parameter increases with the increase of Mn content.With the increase of Mn content,the Neel temperature increases,while the Curie constant and the effective magnetic moment decrease.The x=0.04,existence of three phase transition processes in the low temperature region,and the phase transition temperatures are 34K,18K and 7K,respectively.2.DyMnO₃ doped with a small amount of Mn ions at A-site and doped with Cu at B-site,to form(Dy_0.86Mn_0.14)Mn_1-xCu_xO_3-?solid solution,with a maximum solid solubility of 0.144.The solid solution can be indexed to the orthorhombic structure with the Pnma space group.With the increase of Cu content,a and c lattice parameter decrease,and b lattice parameter increases.The Neel temperature increases with the increase of Cu content,while the Curie constant and the effective magnetic moment decrease with the increase of Cu content.Three dielectric anomalies exist in(Dy_0.86Mn_0.14)Mn_1-xCu_xO_3-?solid solution.