The presence of BCT martensite in Fe-Pd-based ferromagnetic shape memory alloys (FSMA), which develops at lower temperatures than the martensitic transition (MT), deteriorates the shape memory properties. In a previous work performed in Fe₇₀Pd₃₀, it was shown that a thermal treatment above 600 K clearly stabilizes the alloy, reducing the FCT-BCT transformation temperature [1].

In the present work, a study concerning to the stabilization possibilities of Fe₆₇Pd₃₀Co₃ and Fe_66.8Pd_30.7Mn_2.5 FSMA, is carried out, by means of mechanical spectroscopy (MS) and differential thermal analysis (DTA). Indeed, Fe₆₇Pd₃₀Co₃ and Fe_66.8Pd_30.7Mn_2.5 exhibit a lower (250 K) and a higher (310 K) MT temperature, respectively; than the Fe₇₀Pd₃₀. Several thermal cycles involving heating and cooling runs, up to different maximum temperatures are performed in MS and DTA in as-quenched samples.

Polycrystalline ingots of nominal composition (at.%) Fe₇₀Pd₃₀, Fe₆₇Pd₃₀Co₃, Fe_66.8Pd_30.7Mn_2.5 were prepared from high purity elements by arc melting under protective Ar atmosphere. The ingots were homogenized in vacuum quartz ampoules at 1273K during 24 hours and subjected to a 30 minutes annealing treatment at 1173K in a vertical furnace, followed by quenching into iced water.