摘要
研究了偏氯乙烯-三氟乙烯共聚物与钛酸铅形成的铁电复合物PT／P[VDF(70)-TrFE(30)]的热释电流行为．P[VDF(70)-TrFE(30)]室温下存在两个铁电相，即较无序的铁电相和较有序的铁电相，升温经过各自的相转变点后转变成较有序的顺电相和较无序的顺电相．热释电流谱上出现在95℃和108℃的两个电流峰，分别由两个铁电相的结构陷阱以及部分取向的偶极所贡献．采用Tc以上温度极化并冷却到不同温度的方法可明确鉴别出该试样两个顺电相降温转变过程，转变点分别为62℃和50℃．实验证实陷阱仅存在于铁电相而不存在于顺电相中．钛酸铅的引入虽不导致新电流峰出现，但可使共聚物的Tc降低、电流加大．热释电流方法可非常灵敏地跟踪铁电共聚物的相变过程．
The thermally stimulated current (TSC) behaviors of PT/P [VDF (70) - TrFE(30)] composite were investigated systematically. Two kinds of the ferroelectric phase (less organized ferroelectric and organized ferroelectric phase) coexist in the copolymer matrix at room temperature. The phase transitions can be identified clearly by poling sample above the Curie point and then cooling it to different temperatures.The result shows that the para-toferroelectric transitions on cooling appear at 62℃ and 50℃, and ferro -to -paraelectric transitions on heating at about 95℃ and 108℃, respectively. It also indicates that traps exist in ferroelectric phase but not in paraelectric phase of the copolymer. Lead titanate (PT) does not contribute to the current peaks within the experimental temperature range, but it makes Tc decrease and causes the current density increase compared with the pure copolymer.
基金
国家自然科学基金
关键词
偏氟乙烯-三氟乙烯共聚物
钛酸铅
相变
热释电流
P(VDF/TrFE) copolymer
Lead titanate
Ferroelectric transition
Thermally stimulated current
