Specific heat and entropy change at the first order phase transition of La(Fe-Mn-Si)(13)-H compounds
| Autor: | Vittorio Basso, Cecilia Bennati, Milan Bratko, Michaela Küpferling, M. Katter, Carmen Curcio, Alexander Barzca, Lesley F. Cohen, J.A. Turcaud, Edmund Lovell |
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| Přispěvatelé: | Commission of the European Communities |
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Phase transition
Materials science Magnetocaloric properties General Physics and Astronomy Thermodynamics 02 engineering and technology Calorimetry 01 natural sciences Isothermal process Mathematical Sciences Physics Applied Entropy (classical thermodynamics) Engineering 0103 physical sciences Thermoelectric effect Magnetic refrigeration Alloys Applied Physics 010302 applied physics Science & Technology Transition temperature Physics Hysteresis 021001 nanoscience & nanotechnology Magnetic field Physical Sciences 0210 nano-technology |
| Popis: | In this paper, we present the results of an experimental investigation on the magnetocaloric properties of hydrogenated La(Fe-Mn-Si)13-H with Mn substituting Fe to finely tune the transition temperature. We measured the specific heat under magnetic field cp(H, T) and the magnetic field induced isothermal entropy change Δs(H, T) of a series of compounds by direct Peltier calorimetry. Results show that increasing Mn from 0.06 to 0.46 reduces the transition temperature from 339 K to 270 K whilst the total entropy change due to a 1.5 T field is depressed from 18.7 J kg−1 K−1 to 10.2 J kg−1 K−1 and the thermal hysteresis similarly is reduced from 1.5 K to zero. In the paper, we interpret the results in terms of a magnetic phase transition changing from the first to the second order with increasing Mn content, and we discuss the value of the results for magnetic cooling applications. |
| Databáze: | OpenAIRE |
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