Composites perovskites materials: Potential applications in the magnetic cooling technology

It is known that the refrigeration plays a crucial role in different domains of our everyday life such as residential cooling, consumer goods, automotive industry, medical, electronic applications and much more. In this context, the search for new efficient cooling technologies with low impact on the environment constitutes a major challenge for the refrigeration industry. Based on the magnetocaloric effect (MCE), magnetic cooling is becoming a serious alternative for conventional refrigeration systems which is due mainly to its high efficiency and environmental friendliness [1,2]. Nowadays, perovskite manganites have attracted a great attention due to their colossal magnetoresistance (CMR) and strong MCE [3]. Besides the intrinsic CMR effect, a significant intergrain MR (IMR) has also been observed in polycrystalline manganites, which is associated with the spin-dependent charge transport across the grain boundaries [4]. In this talk, the magnetocaloric properties of manganites-based composites are studied, using CuO as secondary phase. The microstructural analysis unveils that the phase is mainly present in the grain boundaries and segregates region. Therefore, the mixture of manganites materials with a small amount of CuO enables to markedly enhance the magnetocaloric effect by favoring the grains growth. The obtained results could inspire new ways for the improvement of the MCE and to tailor the intrinsic properties of manganites.

[1]. K. El Maalam, M. Balli, S. Habouti, M. Dietze, M. Hamedoun, E.-K. Hlil, M. Es-Souni, A. El Kenz, A. Benyoussef, O. Mounkachi, “Composite (La0.45Nd0.25)Sr0.3MnO3/5CuO materials for magnetic refrigeration applications”, Journal of Magnetism and Magnetic Materials 449 (2018) 25–32 ;

[2]. O. Chdil, M. Balli, P. De Rango, K. El Maalam, A. El Boukili, O. Mounkachi, “Assessment of near Pr2/3Sr1/3MnO3 oxide in magnetic cooling”, International Journal of Refrigeration 133 (2022) 302-312 ;

[3]. R. M’nassri, N. Chniba Boudjada, A. Cheikhrouhou, Impact of sintering temperature on the magnetic and magnetocaloric properties in Pr0.5Eu0.1Sr0.4MnO3 manganites, J. Alloy. Compd. 626 (2015) 20–28 ;

[4]. L.W. Lei, Z.Y. Fu, J.Y. Zhang, H. Wang, Synthesis and low field transport properties in a ZnO-doped La0.67Ca0.33MnO3 composite, Mater. Sci. Eng., B 128 (2006) 70–74.

About speaker:

Khadija El Maalam is a physicist and researcher working in the Durability and Engineering of Materials team at the Moroccan Foundation for Advanced Science Innovation and Research, MAScIR. She received her PhD at Mohamed V University in 2016 on development of magnetocaloric materials for magnetic refrigeration application. Currently, she is a project leader for research and development projects : materials/2D materials for energy storage and conversion – materials and nanomaterials for magnetic cooling technology, and a project team member of industrial issues : waste heat storage systems for industrial application – development of an innovative galvanizing coating