| About this Abstract |
| Meeting |
2021 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advanced Materials for Energy Conversion and Storage VII
|
| Presentation Title |
Temperature-induced Successive Martensitic and Inter-martensitic Phase Transformations of Ni2.15Mn0.85Ga Heusler Alloy |
| Author(s) |
Amila Madiligama, Pnina Ari-Gur, Yang Ren, Vladimir G Shavrov, Victor V Koledov, Yanling Ge, James George |
| On-Site Speaker (Planned) |
Pnina Ari-Gur |
| Abstract Scope |
Ni-Mn-based Heusler alloys have attracted much attention due to their functional properties, such as magnetic shape memory and magnetocaloric effects. The studied alloy, Ni2.15Mn0.85Ga, has shown great potential as a magnetocaloric material (ΔQ = 4900 J/kg at 343 K, and under140 kOe field). Upon cooling, the paramagnetic cubic (L21), austenite transforms into ferromagnetic 7M modulated monoclinic martensite. This phase is stable in a narrow temperature range, and upon cooling, transforms into a non-modulated ferromagnetic tetragonal (L10) phase. The separation between the equilibrium temperatures of the austenitic and tetragonal martensitic phases is only ~50 K. This alloy undergoes reversible temperature-induced martensitic and inter-martensitic phase transformations with thermal hysteresis of about 25 K. The conclusions from the detailed study of the three phases, their phase transformation temperatures, and the thermal hysteresis, open new opportunities to enhance the magnetocaloric effect by utilizing the entropy associated with multi-structural transformations in Ni-Mn-Ga alloys. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Magnetic Materials, |