Ternary Mn-based Heusler alloys often exhibit a ferromagnetic shape memory effect,which is best studied in Ni2MnGa, a prototype of Heusler alloys. Heusler Alloys: Structure, Properties and Applications opens by analyzing how by substituting nickel for iron, another Heusler alloy emerges, Fe2MnGa, with much richer structural and magnetic properties than Ni2MnGa and a large ferromagnetic shape memory performance in slightly off-stoichiometric compositions.Next, the effects of atomic site disorder on the transport, magnetic, optical, and magneto-optical properties and electronic structures of metallic Cu2MnAl, Ni2MnGa and Ni2MnIn and half-metallic Co2CrAl, Co2MnGa and Co2CrGa Heusler alloy films are been investigated and the findings are discussed.The concluding study presents first-order reversal curve diagrams of the full-Heusler alloy nanoparticles synthesized by co-precipitation method, followed by thermal annealing at 700 °C under Ar/H2 atmosphere. Interacting single domain particles were dominantly detected from analysis.