Registration Number
0225U005355,
(0125U001287)
, R & D reports
Title
Magnetocaloric and barocaloric effects for energy-efficient solid-state cooling systems
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Розробка та вдосконалення теоретичної моделі, основаної на фундаментальних термодинамічних рівняннях та моделі машинного навчання для дослідження магніто- та барокалоричних ефектів
Head
Velyhotskyi Dmytro V., Кандидат технічних наук
Registration Date
30-12-2025
Organization
V.G. Baryakhtar Institute of Magnetism of the National Academy of Sciences of Ukraine (IMag NAS of Ukraine)
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The goal of the project is to develop a new approach for finding new materials for energy-efficient solid-state cooling systems based on magnetocaloric and barocaloric effects in functional materials with magnetostructural and magnetoelastic phase transitions. And to develop a facility for studying the magnetocaloric and barocaloric effects for solid-state cooling systems.
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A physically structured neural network model has been developed to predict the adiabatic temperature change ΔTad in magnetocaloric materials based on alloy composition and the physical properties of the samples. The model was validated using a set of experimental data.
The dependence of the magnetic, transformational, and thermodynamic properties of Ni50Mn50-xSnx alloys on Sn composition was investigated experimentally. The results demonstrate that, with increasing Sn content, the long-range antiferromagnetic ordering observed at low values of x (x ≤ 8) progressively diminishes and disappears in the range 10 ≤ x ≤ 12.5, accompanied by the emergence of a spin-glass-like state arising from the competition between antiferromagnetic and ferromagnetic interactions.
Six distinct phases of the Ni50Mn50-xSnx system were identified on the temperature–Sn concentration phase diagram, including antiferromagnetic, paramagnetic, and ferromagnetic martensite, a spin-glass state, as well as paramagnetic and ferromagnetic austenite.
Low-temperature specific heat measurements of Ni50Mn50-xSnx alloys (0 ≤ x ≤ 25) revealed linear trends in the weakly magnetic martensitic phase: the electronic specific heat coefficient γ increases with increasing Sn content, whereas the Debye temperature TD decreases. In contrast, in the ferromagnetic austenitic phase, TD remains nearly composition-independent, while γ is significantly enhanced.
Product Description
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Anna O. Kosohor
Viktor I. Hrebynakha
Oleksandr P. Stelmakh
Vladyslav Zamorskyi
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2025-12-30
