Structural properties of magnetic Heusler alloys

Magnetically driven actuator materials, such as the ternary and intermetallic Heusler alloys with composition X2YM, are studied within the density-functional theory (DFT) with the generalized gradient approximation (GGA) for the electronic exchange and correlation. The geometrical and electronic structures for the magnetic L21 structure are calculated. The structures and magnetic moments at equilibrium are in good agreement with the experimental values. The structural trends with varying X and Y are explained by a d-occupation model, while a rigid-band model can account for the trends with changing M.