【摘要】 用传统陶瓷工艺制备了Pb[(Mn1/3Nb2/3)0.5(Mn1/3Sb2/3)0.5]x(Zr0.825Ti0.175)1-xO3(其中x为B位掺杂的摩尔分数,下同)系铁电陶瓷,研究了室温条件下电滞回线的特性。结果显示:当x≤0.1时,电滞回线出现“束腰”;当x=0.2时,“束腰”消失。用X射线光电子能谱、X射线衍射分析手段研究了“束腰”现象,并用氧缺位内偏场理论分析该现象的微观机理。结果表明:过量Mn偏析于晶界,使材料的晶界具有p型导电性,偏析Mn的量越多,晶界p型导电性越强,氧缺位钉扎电畴的能力下降,电畴容易反转,进而导致“束腰”现象消失。另外,随着x增大,剩余极化强度先增大后减小,矫顽场逐渐增大。更多还原

【Abstract】 The Pb[(Mn1/3Nb2/3)0.5(Mn1/3Sb2/3)0.5]x(Zr0.825Ti0.175)1-xO3(x is molar ratio of B-site doping)ferroelectric ceramics were fabri-cated by the conventional technique.The ferroelectric hysteresis at room temperature was investigated.It was shown that the ferroelectric hysteresis constriction appears when x≤0.1,but it vanishes when x=0.2.Electron spectroscopy for chemical analysis and X-ray diffraction techniques were employed to study the ferroelectric hysteresis constriction,and internal mechanism of this constriction phe-nomenon was explained by oxygen vacancy internal bias field model.The results indicate that the grain boundaries present p-type conductivity because of the aggregation of the excess Mn.The greater the amount of segregated Mn,the stronger the p-type conduc-tance,and the smaller the pined domain by oxygen vacancy,the easier the domain switching,resulting in the disappearance of the ferroelectric hysteresis constriction.Otherwise,with the increase of x,the remanent polarization increased first and then decreased,and the coercive field increased gradually.更多还原