Invited Speaker

Abstract: Cold production goes through refrigerant gases (coolants) describing a classic Carnot cycle. These gases are unfortunately harmful and cause the "greenhouse effect" as soon as they escape from their containers during production or in the various heat exchange devices already manufactured. It is therefore urgent to find alternatives; less energy consuming and environmentally friendly solutions. Ferroelectric materials constitute a solution due to their electrocaloric property in solid phase, described by the presence of permanent dipole moments. The ferroelectric-paraelectric phase transition takes place by a crystal symmetry break and a heat exchange takes place in the material, in a reversible process which can be exploited for cooling applications. To the latent heat at phase transition is added the temperature variation due to the change of entropy, compensated by the creation of phonons entropy in the material in a reversible transformation with a constant internal energy.
In order to have amplification of the electrocaloric effect, several avenues are currently being explored, in particular; studies on composites and multiferroics and heterostructures.
In this presentation we will show the recent results obtained on ceramics manufactured from a powder mixture of nanometric grain size that were ferroelectric oxides well chosen (for example, BCT and BCZT) for optimal dielectric and electro-caloric performances. We will also show the perspectives of this study

Keywords: Cooling, Electrocaloric, Nanomaterial, Multiferroic, Heterostructure

Biography: Dr. Yaovi GAGOU is a specialist in electrical measurements and magnetic characterization. His research field are on the theme of Multiferroic Oxides (Perovskite, Aurivillius, tungsten Bronze, etc.) as ceramic, thin layer and superlattices for memory applications, energy storage, photovoltaics and electrocaloric. He is co-author of more than 102 publications in scientific journals (including 82 articles, 1 book, 1 book chapter, 8 conference reports). He has participated as a guest speaker at several international congresses on materials physics and has received more than 535 citations, with an RG Score of 32.82 and an H-index of 13.