Akram Khodayari

Electrocaloric response of the PMN-10PT is measured experimentally and compared with the numerical results. Based on the compatibility of the experimental and numerical results, feasibility of using ferroelectric materials as an electrothermal transducer has been investigated. In this study, electrocaloric response of three different ferroelectric capacitors (PMN-10PT, PMN-25PT, and PZN-4.5PT) under an applied periodic electric field have been investigated. Alternative switching of the electrocaloric elements with specific boundary conditions generates a directed heat flux. It can be concluded that each ferroelectric material can be used as a transducer in a special temperature range that in which it has good electrocaloric response.

This work deals with energy harvesting from temperature variations using ferroelectric materials as a microgenerator. The previous researches show that direct pyroelectric energy harvesting is not effective, whereas thermodynamic-based cycles give higher energy. Also, at different temperatures some thermodynamic cycles exhibit different behaviours. In this paper pyroelectric energy harvesting using Lenoir and Ericsson thermodynamic cycles has been studied numerically and the two cycles were compared with each other. The material used is the PMN-25 PT single crystal that is a very interesting material in the framework of energy harvesting and sensor applications.

In this paper, the feasibility of using ferroelectric materials as a cooling device or solid-state refrigerator based on the electrocaloric effect has been considered. The electrocaloric responses of two different ferroelectric capacitors (PMN-25PT, PZN-4.5PT) are studied. In this study, the dynamics of temperature variation at the edges of a layered structure comprised of an electrocaloric material with heatconducting elements on its sides to an applied periodic electric field have been studied. Electrocaloric elements can generate directed heat flux as a thermal pump by alternative switching. A temperature reduction of 6° is obtained in an electric field of 1 KV/mm at a frequency of 1 Hz for PMN-25PT material after applying 80 cycles. It is shown that the type of applied electric pulses and ferroelectric material affect the results.