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) |
|---|---|
| Pages (from-to) | 952-956 |
| Number of pages | 5 |
| Journal | Intermetallics |
| Volume | 19 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jul 2011 |
Funding
PZ, PM, and DCD acknowledge financial support of the National Science Foundation, Division of Materials Research grant No. NSF-DMR 0804984 (Boise State University) and grant No. DMR-0805064 (Northwestern University). CPS and VB acknowledge that the research leading to these results received funding from the European Community 7th Framework Programme under grant agreement 214864 (project SSEEC).
Keywords
- A. Magnetic intermetallics
- B. Magnetic properties
- B. Martensitic transformations
- F. Calorimetry
ASJC Scopus subject areas
- General Chemistry
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry