"An influence of the Cu doping on structural, magnetic and thermoelastic properties of the Heusler Ni44-xCuxCo6Mn39Sn11 (x = 1–4 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 Ni–Co–Mn–Sn 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−1K−1 for Cu2."