摘要
建立起激光强度调制法测量装置及其测量与数据处理方法，研究了 Ｖ Ｄ Ｆ／ Ｔｒ Ｆ Ｅ 铁电共聚物的极化分布和退极化过程．发现２５ μｍ 厚的 Ｖ Ｄ Ｆ（８０）／ Ｔｒ Ｆ Ｅ（２０） 薄膜在距表面８ μｍ 左右薄层热电系数显示极大值，而１２ μｍ 厚的则在中心处，两者的热电系数皆以两表面呈对称分布．在１４５ ℃热处理产生退极化．随着时间的增长，热电系数减小，退极化由试样的一面向另一面逐渐进行，２ ｈ 后由强电场形成的极化基本消失．直流极化３０ μｍ 厚的 Ｖ Ｄ Ｆ（７０）／ Ｔｒ Ｆ Ｅ（３０） 薄膜，热电系数分别在离两表面６ ，８ μｍ 处达恒定值，基本以两表面呈反对称分布．
Measuring system and method as well as data processing of the laser intensity modulation method(LIMM) have been set up.The polarization distribution and the process of depolarization for VDF/TrFE ferroelectric copolymers are investigated by LIMM.The pyroelectric coefficient shows a maximum at a distance of about 8?μm from the two surfaces of 25?μm\|thick VDF(80)/TrFE(20) sample,while it shows a maximum at the centre for 12?μm\|thick one.The polarization displays a symmetric pyroelectric distribution.Annealing at 145?℃ introduces depolarization.The pyroelectric coefficient decreases gradually from one side of the sample to the other with increasing annealing time and disappears at about 2?h later.The pyroelectric coefficient for 30?μm\|thick VDF(70)/TrFE(30) film poled by dc electric field at room temperature tends towords a constant at 6?μm and 8?μm from the two surfaces of the sample respectively,and produces an antisymmetric pyroelectric distribution. PACC: 7730; 7770; 4260F
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
1999年第9期1760-1766,共7页
Acta Physica Sinica
基金
国家自然科学基金
香港 RGC资助
香港理工大学资助
