The effect of DO$_3$/ L2$_1$ phase separation on the martensitic transition of Cu-A1-Mn shape-memory alloys

In this paper we show that a magnetic-induced phase separation between Cu$_3$A1-rich and Cu$_2$A1Mn-rich domains occurs below the $L2_1$-ordering temperature in alloys with compositions along the Cu$_3$A1$\rightarrow$Mn line. We study the influence of such a phase separation on the magnetic properties and on the martensitic transition undergone by Cu-A1-Mn alloys. Results indicate that during the phase separation process, the ferromagnetic character of the system is enhanced as a consequence of the formation of Mn-rich clusters. This leads to an increase in the martensitic transition temperature and to a decrease of the entropy change