Title :
Temperature dependence of piezoelectric constants for polyureas synthesized by vapor deposition polymerization
Author :
Fukada, Eiichi ; Wang, Xian-Shan ; Hattori, Takeshi ; Iijima, Masayuki ; Takahishi, Y.
Author_Institution :
Inst. for Super Mater., ULVAC, Tsukuba, Japan
Abstract :
Thin films of aromatic and aliphatic polyureas are prepared by the evaporation and deposition of a diamine monomer and a diisocyanate monomer onto a polyimide substrate in a vacuum chamber. Application of a high electric field induces the films a residual polarization due to the alignment of urea bond dipoles. The piezoelectric constants for aromatic polyureas are almost unchanged from -150°C to 200°C. While those for aromatic polyureas show relaxational change due to the thermal molecular motions
Keywords :
dielectric polarisation; dielectric thin films; piezoelectric materials; piezoelectric thin films; polymer films; polymerisation; vacuum deposited coatings; -150 to 200 C; aliphatic polyureas; aromatic polyureas; deposition; diamine monomer; diisocyanate monomer; evaporation; piezoelectric constants; polyimide substrate; polyurea; relaxational change; residual polarization; temperature dependence; thermal molecular motions; thin films; urea bond dipoles alignment; vapor deposition polymerization; Aluminum; Chemical vapor deposition; Electrodes; Hydrocarbons; Piezoelectric films; Polyimides; Polymer films; Substrates; Tellurium; Temperature dependence;
Conference_Titel :
Electrets, 1994. (ISE 8), 8th International Symposium on
Conference_Location :
Paris
Print_ISBN :
0-7803-1940-0
DOI :
10.1109/ISE.1994.515216
