Pr含量对Bi_5Fe_(0.5)Co_(0.5)Ti_3O_(15)室温多铁性的影响

采用改良的固相烧结工艺制备了Bi5-xPrxFe0.5Co0.5Ti3O15(BPFCT-x,x=0.25,0.50,0.75,0.80)陶瓷样品.X射线衍射结构分析表明:镨(Pr)含量对样品微观结构产生了影响,但所有样品均为层状钙钛矿结构;BPFCT-x样品的剩余极化强度(2Pr)随着掺杂量的增加呈现出先增大后减小的变化趋势,当Pr含量为0.75时,样品的2Pr达到最大值,为6.43μC/cm2.样品的磁性与铁电性能具有相同的变化规律,室温下样品的剩余磁化强度(2Mr)也呈现出先增大后减小的趋势,并且也在x=0.75时达到最大为0.097 emu/g.随着Pr掺杂量增大,样品的室温下铁电和铁磁性能得到明显改善,并且当掺杂量为0.75时,样品室温多铁性最好.Pr掺杂降低了样品中的缺陷浓度,从而提高了样品铁电畴动性,这有助于提高样品铁电性能.而样品铁磁性能的改善可能与Pr对样品晶格畸变产生的影响有关.

Effect of doping Pr on multiferroic properties of Bi5Fe0.5Co0.5Ti3O15 ceramics at room temperature

The polycrystalline Bi_5-xPr_xFe_0.5Co_0.5Ti₃O₁₅ (BPFCT-x: x=0.25, 0.50, 075, 0.80) ceramics are prepared by an improved solid state reaction method. X-ray diffraction structure analysis shows that the content of Pr has an influence on the microstructure of sample, but all the samples are layered perovskite structure. The remanent polarization (2P_r) first increases and then decreases with the increase of Pr content (x), so do the magnetic and ferroelectric properties. The remanent polarization reaches a maximum vaule of 6.43 μC/cm², when x = 0.75. The remanent magnetization (2M_r) increases to a maximum value of 0.097 emu/g when x=0.75, and then decreases with the increase of Pr content (x). with the increase of Pr doping the ferroelectric and ferromagnetic properties of sample at room temperature can be obviously improved, and when x=0.75, multiferroic properties of the sample at room temperature is the best. The improvement in ferroelectric properties of sample is related to Pr doping. With the increase of Pr content (x), the defect concentration of the sample can be reduced, ferroelectric domain of movement can be improved, and the improvement in ferromagnetic property is possibly related to the lattice deformation which is affected by Pr.
Keywords： doping ferroelectric property magnetism dielectric property