Transformation behavior and inverse caloric effects in magnetic shape memory Ni44-xCuxCo6Mn39Sn11 ribbons

An influence of the Cu doping on structural, magnetic and thermoelastic properties of the Heusler Ni44xCuxCo6Mn39Sn(x ¼ 1e4 at%) ribbons has been investigated. It is found that the addition of Cu stabilizes austenite phase. Martensite transformation (MT) temperatures generally decrease when Cu concentration increases, which is attributed to the atom size effect. The inverse magnetocaloric and elastocaloric effects in the vicinity of MT under moderate magnetic fields and stresses have been evaluated. Small Cu addition enhances both effects as compared to quaternary NieCoeMneSn alloy. The magnetic entropy change under low magnetic field of 15 kOe increases from 2.9 J kg- 1K-1 for Cu0 to 6.3 J kg -1 K -1 for Cu2.