Structural properties of magnetic Heusler alloys

Magnetically driven actuator materials, such as the ternary and intermetall ic Heusler alloys with composition X2YM, are studied within the density-fun ctional theory (DFT) with the generalized gradient approximation (GGA) for the electronic exchange and correlation. The geometrical and electronic str uctures for the magnetic L2(1) structure are calculated. The structures and magnetic moments at equilibrium are in good agreement with the experimenta l values. The structural trends with varying X and Y are explained by a d-o ccupation model, while a rigid-band model can account for the trends with c hanging M.