Pyroelectricity in Nylon 7 and Nylon 11 ferroelectric polymers

The temperature and frequency dependences of the pyroelectric current have been studied in Nylon 7 and Nylon 11 ferroelectric polymer films. A remarkable change of value of the pyroelectric currents near the glassy transition temperature (Tg) was observed. Analyses of experimental data show that the temperature behavior of pyroelectric currents can be explained by the competition of the primary and secondary effects. Currents due to these effects have different signs. Below Tg, the dominant component of the pyroelectric current is primary pyroelectricity, and above Tg the secondary effect becomes dominant. Mechanisms producing pyroelectric currents in Nylon 7 and Nylon 11 are discussed.