Magnetoresistance of the Fe72Cu1V3Si16B8 amorphous alloy annealed by direct current Joule heating

Abstract The longitudinal magnetoresistance of the Fe 72 Cu 1 V 3 Si 16 B 8 melt spun ribbon in its as-cast and nanocrystalline state has been studied. Successive thermal treatments with increasing in current intensity from 33 to 43 A/mm 2 were applied for a fixed time ( t an =180 s) in order to evolve nanocrystalline structure. Nanocrystals are detected by X-ray diffraction after treatment around 760 K. The volumetric fraction of the crystalline phase was calculated from the effective resistivity of the sample and by enthalpy data. The increases of α-Fe(Si) crystallites over 38% with residual amorphous matrix lead to the sign change from positive to negative magnetoresistance. The saturation in concentration of silicon in precipitated α-Fe crystallites to the value of 19 at % Si has been observed.