Phase stability of B2 and L21 ordered phases in Co2YGa (Y=Ti, V, Cr, Mn, Fe) alloys

The B2/L21 order–disorder and magnetic transitions in Co2YGa (Y=Ti, V, Cr, Mn, Fe) alloys were investigated by electron probe microanalysis (EPMA), differential scanning calorimetry (DSC) and vibrating sample magnetometry (VSM). It was confirmed that the B2/L21 order–disorder transition temperature for the Co2YGa (Y=Ti, V, Cr) alloys monotonically decreases with increasing electron concentration of the Y site, whereas that of the Co2YGa (Y=Mn, Fe) alloys is almost constant at 1100 ± 100 K. On the other hand, the Curie temperature TC of all the alloys rises almost monotonically with increasing electron concentration of the Y site.