Dresden 2026 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 52: Poster Magnetism III
MA 52.25: Poster
Donnerstag, 12. März 2026, 15:00–17:00, P4
MnCrNiGeSi high-entropy alloy: structural, magnetic and magnetocaloric properties — •Atakan Tekgül1 and Kağan Şarlar2 — 1Uludag University, Bursa, Turkey — 2Karamanoglu Mehmetbey University, Bursa, Turkey
This study investigates the structural, magnetic, and magnetocaloric properties of two rare-earth-free high-entropy alloys, Mn20Cr14Ni33Ge25Si5 and Mn24Cr10Ni33Ge25Si8, produced by arc melting. Rietveld refinement of X-ray diffraction data confirms that both alloys crystallize in an orthorhombic Pnma structure. Increasing the Mn content from 20% to 24% strengthens the ferromagnetic exchange interactions, resulting in an enhancement of the saturation magnetization (43.8->56.7 Am−1kg−1) and an upward shift of the Curie temperature (361->387 K). Isothermal magnetization measurements and Arrott plot analyses reveal a second-order magnetic phase transition. The magnetocaloric effect, calculated via the Maxwell relation, yields a magnetic entropy change of 2.1 Jkg−1K−1 for the alloy with 20% Mn and 3.6 Jkg−1K−1 for the Mn-rich alloy under a magnetic field of 2 T. The combination of low hysteresis, high Curie temperature, and enhanced entropy change demonstrates that Mn-enriched Mn-Cr-Ni-Ge-Si HEAs offer promising performance for environmentally friendly, high-temperature magnetic refrigeration. These results confirm that compositional tuning, particularly Mn substitution, is an effective route for optimizing the magnetocaloric response in rare-earth-free HEAs.
Keywords: Magnetocaloric effect; High-entropy-alloy; high temperature alloy