A HEAT-WAVE METHOD FOR THE MEASUREMENT OF THERMAL AND PYROELECTRIC PROPERTIES OF PYROELECTRIC FILMS

An experimental technique is presented, which enables the simultaneous or consecutive measurement of the specific heat and thermal diffusivity, and of the pyroelectric coefficient and its spatial distribution in the same sample. The pyroelectric samples are in the form of thin films. The metal electrodes on the front and rear surface of the film are designed as thin film bolometers. The film is heated at one surface with intensity modulated radiation. With the film bolometers the temperature amplitude at the front and at the rear surface of the sample are measured. Simultaneously or consecutively the pyroelectric current is measured as a function of the modulation frequency. From the measured spectra, the thermal diffusivity, the pyroelectric coefficient and its spatial distribution inside the film can be calculated. The experimental method is applied to PVDF foils, the thermal and pyroelectric data of this polymer are analyzed as a function of the temperature. © 1990, Taylor & Francis Group, LLC. All rights reserved.