Preparation And Properties Of Ferrous Barium Strontium Titanate-Based Functional Ceramics

Multiferrioc material is a kind of multifunctional material that possesses both magnetic and electric properties.Ferroelectric/piezoelectric materials are electrically insulated.ferroelectric/piezoelectric materials are electrically insulating and magnetic materials are electrically conductive,so the two types of materials are incompatible.Multiferrioc material integrate these two different characteristics into one,showing the orderly coexistence of two or more kinds of iron properties such as ferroelectricity,ferromagnetism,and iron bomb.More importantly,new effects will be generated due to the interaction between multiple order parameters.In this paper,the strontium barium titanate/neodymium ferrite bismuth?BST/BNFO?composite with different concentrations of strontium titanate?SrTiO₃?were prepared by a conventional solid-state reaction process.The spontaneous polarization strength and magnetic properties of the composite were improved by adjusting sintering temperature and composition,so as to produce multi-ferroic materials with strong magneto-electric coupling.The ceramic materials were prepared by doping the magnetic material(BaFe₁₂O₁₉?Bi_0.8Nd_0.2FeO₃)in the ferroelectric materials?BST?with the optimal sintering performance.?1?A series of 0.97 Ba_1-xSr_xTiO₃ and BaFe₁₂O₁₉co-doped ceramic materials were prepared by high temperature solid phase method.Strontium barium titanate/neodymium ferrite bismuth?BST/BFO?composite materials doped with strontium titanate?SrTiO₃?of different concentrations were prepared.The effects of different SrTiO₃ doping amounts on the ferromagnetism and ferroelectricity of the materials as well as the effects of different sintering temperatures on the ferromagnetism of the materials were investigated.The experimental results showed that the prepared BST/BFO series ceramics exhibited both good ferromagnetism and ferroelectricity at room temperature.With the increase of SrTiO₃ doping amount,the ferromagnetism and ferroelectric properties of the samples were enhanced.Where,when x=0.20,the remanent magnetization intensity of the sample is the highest,and Mr=1.42emu/g.The sample shows good magneto-electric coupling performance.The sample shows good magneto-electric coupling performance.?2?A series of ceramic samples co-doped with 0.97 Ba_1-xSr_xTiO₃ and Bi_0.8Nd_0.2FeO₃ were prepared by high temperature solid phase method.Strontium barium titanate/neodymium ferrite bismuth?BST/BNFO?composites doped with strontium titanate?SrTiO₃?at different concentrations were prepared.The results show that the BST/BNFO series ceramics show good ferromagnetism and ferroelectricity at room temperature.With the increase of SrTiO3 doping amount,the ferromagnetism of the sample was enhanced,and the ferroelectric property was weakened or even disappeared.Therefore,when X=0.25,the saturated magnetization of the sample reaches its maximum value,which is 2.5emu/g.The sample shows greater ferromagnetism and better ferroelectricity,and the residual magnetization Mr=0.9emu/g.The relative dielectric constant of BST/BNFO ceramics under magnetic field and without magnetic field has obvious change rule.