【摘要】 采用传统固相烧结法制备Bi1-xDyxFeO3(x=0,0.05,0.1,0,0.15)陶瓷样品.分别对样品的介电性能、铁电性进行了测量与分析.结果表明:Bi1-xDyxFeO3样品主衍射峰与纯相BiFeO3相吻合且具有良好的晶体结构;BiFeO3样品的介电常数、介电损耗均随Dy3+掺杂量的增加而逐渐增大.在测试频率为103Hz条件下,Bi0.85Dy0.15FeO3(εr=3 305)的rε是BiFeO3(rε=54.2)的50倍;BiFeO3样品2Pr随x的增加而明显增大,当x=0.1,0.15时,样品2Pr分别是BiFeO3的30倍,矫顽电场分别是BiFeO3的3,4倍.其原因主要是Dy3+稳定性优于Bi3+,Dy3+A位替代减少Bi3+挥发而降低氧空位浓度,减小样品的电导和漏电流,进一步提高BiFeO3样品的铁电特性.更多还原

【Abstract】 Multiferroic Bi1-xDyxFeO3(x=0,0.05,0.1,0.15) ceramics are prepared by solid state reaction.The crystalline structure of all samples is characterized by using XRD.Frequency dependence of dielectric properties of all samples is measured with a HP4294A precision impedance analyzer.A Radiant RT 6000 ferroelectric analyzer is applied to measure the hysteresis loops of different samples.The results show that: X-ray diffraction is carried out to characterize the crystal structure and to detect any possible impurities present in these ceramics.For all the samples studied,the dielectric constant decrease and dielectric loss increase with increasing frequency in the range from 1 000 Hz to 1 MHz,can be expected from a typical orientational dielectric relaxation process.It has been found that both dielectric constant and dielectric loss are strongly dependent on the Dy3+ content.A saturated P-E hysteresis loop is obtained with Bi1-xDyxFeO3(x=0,0.05,0.1,0.15) samples,with a large remanent polarization(Pr) of 2.3μC/cm2 at an applied electric field of 28 kV/cm,indicating Dy3+doping enhances the ferroelectricity of BiFeO3 system.更多还原