Modeling and characterization of the magnetocaloric effect in Ni2MnGa materials

• Calculations indicate that Ni2MnGa can have a significant MCE even without the structural contributions.
• We highlight the flexibility of transition temperatures with composition.
• A 5 K adiabatic temperature change is reported for 9 T change in field.
• Differential scanning calorimeter, SQUID, and elastic neutron scattering data are presented for Ni2MnGa with alloy additions.

Magnetic shape memory alloys have great promise as magneto-caloric effect refrigerant materials due to their combined magnetic and structural transitions. Computational and experimental research is reported on the Ni2MnGa material system. The magnetic states of this system are explored using the Wang-Landau statistical approach in conjunction with the Locally Self-consistent Multiple-Scattering method. The effects of alloying agents on the transition temperatures of the Ni2MnGa alloy are investigated using differential scanning calorimetry and superconducting quantum interference device. Experiments are performed at the Spallation Neutron Source at Oak Ridge National Laboratory to observe the structural and magnetic phase transformations.