The influence of compressive-stress-induced martensite aging on the two-way shape memory effect in single crystals of Ni$_{49}$Fe$_{18}$Ga$_{27}$Co$_{6}$ ferromagnetic alloy

The influence of stress-induced martensite aging (SIM-aging, SIM-aged) under compressive load in the [110]$_{B2}$ direction on the development of thermoelastic martensitic transformation has been studied in single crystals of Ni$_{49}$Fe$_{18}$Ga$_{27}$Co$_{6}$ ferromagnetic alloy. The experimentally selected effective SIM aging regime ($T$ = 423 K, 1 h, $\sigma$ = 450 MPa) favors the stabilization of oriented stress-induced martensite and induces a tensile two-way shape memory effect (TWSME) with magnitude of +9.0 $\pm$ 0.3% in the [001]$_{B2}$ direction (perpendicular to the SIM aging load axis [110]$_{B2}$). The maximum amount of work performed by the crystal under TWSME conditions can reach $W_{\mathrm{max}}$ = 0.14 J/g (1125 kJ/m$^3$).