Transport properties of Fe₆₀Al₄₀ during the B2 to A2 structural phase transition

The variation of transport behavior in a mesoscopic Fe60Al40 wire, initially possessing the ordered B2 -phase structure, has been observed while inducing a phase transition to the disordered A2 phase. Gradual disordering was achieved using a highly focused beam of Ne+ -ions. Both electrical resistance and anomalous Hall effect were measured simultaneously and in situ during the local ion irradiation. The normal as well as the Hall resistivity show a peak as a function of disorder. The relationship between Hall resistivity and normal resistivity shows the presence of two distinct transport regimes during the phase transition. Ex situ field- and temperature-dependence measurements show that it is necessary to consider the effect of scattering from magnetic clusters to understand these different regimes in transport properties.