A considerable metamagnetic shape memory effect without any prestrain in Ni46Cu4Mn38Sn12 Heusler alloy

Abstract

Spontaneous strains during martensitic transformation and magnetic-field-induced transformation have been systemically studied for Ni46Cu4Mn38Sn12 Heusler alloy, respectively. A large spontaneous strain with the value of about 0.12% upon martensitic transformation has been observed in this alloy, which is almost three times larger than that in ternary Ni–Mn–Sn alloy. In addition, such a value of strain can be obtained through a fully reverse martensitic transformation induced by a field of about 45 kOe, exhibiting a considerable metamagnetic shape memory effect without any prestrain. This behavior can be attributed to magnetoelastic coupling between stable martensite and metastable fraction of austenite.

Effect of electron density on the martensitic transition in Ni–Mn–Sn alloys

“…Adjusting the elemental chemical composition and partial substitution by other elements are two main methods to tune the MT temperatures. In most cases, for example, adjusting the Ni/Mn ratio [11,12], substituting Ni or Mn with Co and Cu [13,14], or replacing In with Sb [15], the variations of the MT temperatures are in accord with the valence electron concentration theory. Actually, the changes of chemical composition or alloying elements can affect not only the electronic structure but also the geometry structure.…”

Temperature and field induced strain in polycrystalline Ni50Mn35In15−xSix magnetic shape memory Heusler alloys

“…Field dependence of the strain measured parallel to the external magnetic field for the sample cut parallel and perpendicular to the direction of sample solidification during arc melting for Ni50Mn35In12Si3. prestrain is significantly higher than that recently reported for polycrystalline Ni-Mn-X (X = In, Sb, Sn, Ga) [for examples, ≈0.1% in Ref [14], and ≈0.2% in Ref. [9]].…”

Tuning martensitic transformation, large magnetoresistance and strain in Ni 50−x Fe x Mn 36 Sn 14 Heusler alloys

“…For x=1, in the presence of magnetic fields, the maximum ∆L/L is as the same as that found in zero magnetic fields, which is due to weakness of win-boundary mobility in Ni-Mn-Sn. For our sample, the strain is larger than those in Ni 49.8 Mn 34.7 Sn 15.5 [33], Ni 46 Co 4 Mn 39 Sn 11 [34].…”