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MA: Fachverband Magnetismus
MA 51: Caloric Effects in Ferromagnetic Materials
MA 51.7: Vortrag
Freitag, 22. März 2024, 11:30–11:45, H 2013
High throughput approach for finding magnetocaloric materials — Rafael Martinho Vieira1, Sagar Ghorai2, Olle Eriksson1, and •Heike C. Herper1 — 1Department of Physics and Astronomy, Uppsala University, Sweden — 2Functional Materials, TU Darmstadt, Germany
After several decades of research, the pool of materials suitable for room-temperature refrigeration is still very limited. Materials with magnetostructural phase transition (MST) are possible candidates for magnetocaloric materials. MnNiSi-based systems undergo a structural phase transition and have the potential for MST. We show that an MST can be reached by Fe and Al doping and for Mn1-xFexNiSi0.95Al0.5 we observe a giant magnetocaloric effect at room temperature. [(https://doi.org/10.48550/arXiv.2307.00128)] By combining experiments with ab initio theory and spin dynamics methods we could show that the key to the large magnetocaloric response lies in the coexistence of the two magnetically very different phases at low temperatures. Based on the findings for MnFeNiSiAl we designed a high-throughput search method to identify candidate phases with MST. Big data searches were combined with first-principles calculations and spin dynamics simulations. [1] About 20 systems with several polymorphs were found. Out of this group, several candidates show potential for an MST near room temperature. Their magnetic properties have been studied in our theoretical approach and will be discussed as well as the expected magnetocaloric performance.
[1] Journal of Alloys and Compounds 857, 157811(2021)
Keywords: Magnetocaloric effect; DFT; High throughput search