Prof. Zdravko Kutnjak: Electrocaloric materials and dielectric refrigeration: novel developments and future perspectives

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Povzetek:   

    Electrocaloric materials and dielectric refrigeration: novel developments and future perspectives 

         (Elektrokalorični materiali in dielektrično hlajenje: novosti in bodoče perspective) 

         Javno predavanje ob izvolitvi v naziv rednega profesorja      

    Prof. Zdravko Kutnjak, Institut Jožef Stefan, Ljubljana, Slovenija

The electrocaloric effect (ECE) in a given material is related to the conversion of the electrical energy into the heat and vice versa. It is referring to a temperature or entropy change of a dipolar material under application and removing of an electric field. Although ECE has been studied for many decades, the relatively small ECE observed <2.5 oC, made it unsuitable for practical applications. Recently, however, materials with large ECE have been predicted to exist based on indirect observations thus opening the possibility of realizing dielectric refrigeration which is more environmentally friendly compared to other techniques. The later direct confirmation of large ECEs in ferroelectric polymers and in ferroelectric ceramic thin films have attracted great interest for developing new cooling devices that have the potential to reach better efficiency than the existing cooling technologies. A review of recent ECE theoretical and experimental findings obtained in various polar materials ranging from solid materials like polymeric and perovskite relaxor ferroelectrics to soft liquid crystalline materials will be given. In addition, recent progress in development of practical dielectric cooling devices utilizing different approaches and materials will be presented.Pred predavanjem vse udeležence vabimo na čaj!