应力对热电体电热效应的影响

Effects of stresses on electrocaloric effects of the thermoelectric body

在一定温度范围内,采用Landau-Devonshire自由能理论,讨论了应变对电场导致的PbZr0.4Ti0.6O3(PZT)以及[P(VDF-TrFE)](65/35)偏氟乙烯和三氟乙烯共聚物薄膜和块材的系统熵的影响,以及熵极大时的温度变化.结果表明:随着应变的增加,聚合物和PZT的场致温变和等温熵变最大值时的温度分别线性增大和减小.为了增大薄膜在较低工作温度下的熵变,要求聚合物的应变大于0,PZT的应变小于0.

In a certain temperature range, using Landau-Devonshire free energy theory, the effects of strain on system entropy of both bulk and thin film of PbZr0.4Ti0.6O3 （PET） and [-P（VDF-TrFE）]（65/35） vinylidene fluoride-trifluoroethylene polymers and temperature change when entropy is maximum have been discussed. The results showed that as strain increases, temperature change caused by electric field and temperature when isothermal entropy change was maximum of polymers and PZT increased linearly and decreased linearly separately. To increase the entropy change of the films when they works at a low temperature, the strain of the polymers should be above zero, and the strain of PZT should he below zero.