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 Ni54.8Mn 20.2Ga25.0 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.
Original language | English (US) |
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Pages (from-to) | 952-956 |
Number of pages | 5 |
Journal | Intermetallics |
Volume | 19 |
Issue number | 7 |
DOIs | |
State | Published - Jul 2011 |
Keywords
- A. Magnetic intermetallics
- B. Magnetic properties
- B. Martensitic transformations
- F. Calorimetry
ASJC Scopus subject areas
- Chemistry(all)
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry