Influence of the corrosion on the saturation magnetic density of amorphous and nanocrystalline Fe<f>73</f>Nb<f>3</f>Si<f>15.5</f>B<f>7.5</f>Cu<f>1</f> and Fe<f>80</f>Zr<f>3.5</f>Nb<f>3.5</f>B<f>12</f>Cu<f>1</f> alloys

Amorphous FeMBCu (M=Nb, Zr) and FeNbSiBCu alloys with nanometer size crystallites have attracted attention due to their soft magnetic properties. The mechanism through which crystallization affects the corrosion and the comparative effect of corrosion on magnetic properties of FeMBCu (M=Nb, Zr) and FeNbSiBCu alloys has not yet been evaluated. In this paper the effect of partial crystallization on corrosion resistance of amorphous Fe<f>73</f>Nb<f>3</f>Si<f>15.5</f>B<f>7.5</f> Cu<f>1</f> and Fe<f>80</f>Zr<f>3.5</f>Nb<f>3.5</f>B<f>12</f>Cu<f>1</f> alloy ribbons and the comparative effect of corrosion on saturation magnetic flux density, Bs, of these alloys were investigated. The samples were characterized by X-ray diffraction, differential scanning calorimetry and X-ray photoelectron spectroscopy. Corrosion resistance evaluation was carried out by measuring mass loss of samples immersed in 0.1 M H<f>2</f>SO<f>4</f> solution, and by measuring potentiodynamic polarization curves (potential vs. current). Saturation magnetic flux density, Bs, of the samples were measured. After partial crystallization of Fe<f>80</f>Zr<f>3.5</f>Nb<f>3.5</f>B<f>12</f>Cu<f>1</f> amorphous sample the corrosion resistance decreased, while for the Fe<f>73</f>Nb<f>3</f>Si<f>15.5</f>B<f>7.5</f>Cu<f>1</f> the corrosion resistance increased. The decrease of Bs after treatment in the corrosion solution as observed in the nanocrystalline Fe<f>80</f>Zr<f>3.5</f>Nb<f>3.5</f>B<f>12</f>Cu<f>1</f> sample was larger than that observed for both amorphous and the nanocrystalline Fe<f>73</f>Nb<f>3</f>Si<f>15.5</f>B<f>7.5</f>Cu<f>1</f> samples after the same treatment. [Copyright &y& Elsevier]