A Comparative Studies of Magnetocaloric Effect in Ni-Mn-Cu-Ga and Ni-Mn-Pb-Ga Alloys |
K. Sielicki, R. Wróblewski, M. Leonowicz
Faculty of Materials Science and Engineering, Warsaw University of Technology, Wołoska 141, 02-507 Warszawa, Poland |
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Effect of Pb substitution for Cu on magnetocaloric properties of Ni2Mn1-xCuxGa (x=0.25, 0.27, 0.29) alloy was investigated experimentally. The magnetic measurements of Ni-Mn-Pb-Ga alloys conducted at low field of 4kA/m (50 Oe) showed that their Curie points are above the room temperature (RT). The analysis of isothermal magnetic curves allowed the estimation of magnetic entropy change (ΔSM). The highest calculated value of |ΔSM|, ≈12 J/(kg K) and ≈1.8 J/(kg K), was registered for alloys containing 6.25 at.% of Cu and 6.75 at.% of Pb, respectively. The adiabatic temperature changes (ΔT) measured near RT are ≈0.4 K. |
DOI: 10.12693/APhysPolA.127.644 PACS numbers: 75.30.Sg |