The high surface/volume ratio and mechanical stability under cyclic strain makes polycrystalline Ni-Mn-Ga metallic foams attractive for magnetic refrigeration. By means of comparison with a polycrystalline bulk material, we have demonstrated that the porous structure of Ni(54.8)Mn(20.2)Ga(25.0) open-cells metallic foams (porosity varying between 44% and 58%) reduces the temperature span of the phase transition and increases the magnetocaloric effect (MCE). MCE was investigated using calorimetry in a magnetic field. Temperature scan and isothermal experiments have shown a 0.8 K T(-1) shift of the phase transition temperature and a maximum irreversible entropy change of 2.5 Jkg(-1) K(-1). The results indicate that metallic foams can represent a good approach for enhancing field induced phase transitions in magnetic refrigeration applications. (C) 2011 Elsevier Ltd. All rights reserved.
Enhanced field induced martensitic phase transition and magnetocaloric effect in Ni55Mn20Ga25 metallic foams / Sasso, CARLO PAOLO; Zheng, P; Basso, Vittorio; Müllner, P; Dunand, D. C.. - In: INTERMETALLICS. - ISSN 0966-9795. - 19:(2011), pp. 952-956. [10.1016/j.intermet.2011.02.015]
Enhanced field induced martensitic phase transition and magnetocaloric effect in Ni55Mn20Ga25 metallic foams
SASSO, CARLO PAOLO;BASSO, VITTORIO;
2011
Abstract
The high surface/volume ratio and mechanical stability under cyclic strain makes polycrystalline Ni-Mn-Ga metallic foams attractive for magnetic refrigeration. By means of comparison with a polycrystalline bulk material, we have demonstrated that the porous structure of Ni(54.8)Mn(20.2)Ga(25.0) open-cells metallic foams (porosity varying between 44% and 58%) reduces the temperature span of the phase transition and increases the magnetocaloric effect (MCE). MCE was investigated using calorimetry in a magnetic field. Temperature scan and isothermal experiments have shown a 0.8 K T(-1) shift of the phase transition temperature and a maximum irreversible entropy change of 2.5 Jkg(-1) K(-1). The results indicate that metallic foams can represent a good approach for enhancing field induced phase transitions in magnetic refrigeration applications. (C) 2011 Elsevier Ltd. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
