Room temperature huge magnetocaloric properties in low hysteresis ordered Cu-doped Ni-Mn-In-Co alloys
The reduction of the thermal hysteresis in first order magnetostructural transition is a determining factor to decrease energy losses and to improve the efficiency of magnetocaloric cooling based systems. In this work, a Cu doped NiMnInCo metamagnetic shape memory alloy (MMSMA) exhibiting a narrow t...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2022 |
| País: | España |
| Institución: | Universidad Pública de Navarra |
| Repositorio: | Academica-e. Repositorio Institucional de la Universidad Pública de Navarra |
| OAI Identifier: | oai:academica-e.unavarra.es:2454/43846 |
| Acceso en línea: | https://hdl.handle.net/2454/43846 |
| Access Level: | acceso abierto |
| Palabra clave: | Martensitic transformation Order-disorder phenomena Heusler alloys Shape memory alloys Magnetocaloric effect |
| Sumario: | The reduction of the thermal hysteresis in first order magnetostructural transition is a determining factor to decrease energy losses and to improve the efficiency of magnetocaloric cooling based systems. In this work, a Cu doped NiMnInCo metamagnetic shape memory alloy (MMSMA) exhibiting a narrow thermal hysteresis (around 5 K) at room temperature has been designed. In this alloy, the induced L21 ordering process affects the phase stability in an unusual way compared to that observed in NiMnInCo and other NiMn based alloys. This ordering produces an increase in the Curie temperature of the austenite but hardly affects the mar tensitic transformation temperatures. As a consequence, the ordering increases the magnetization of the austenite without changing the transformation temperatures, doubles the sensitivity of the transformation to magnetic fields (the Claussius-Clapeyron slope goes from 2.1 to 3.9 K/T), improves the magnetocaloric effect, the reversibility and finally, enhances the refrigeration capacity. In addition, the magnetic hysteresis losses are among the lowest reported in the literature and the effective cooling capacity coefficient RCeff reaches 86 J/Kg for 2 T (15 % higher than those found in Ni-Mn based alloys) and 314 J/Kg for 6 T fields. Therefore, the ordered alloy possesses an excellent combination of low thermal hysteresis and high RCeff, not achieved previously in metamagnetic shape memory alloys near room temperature. |
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