2. Experimental
Amorphous ribbons of different compositions (Table 1) were prepared by melt spinning under an argon atmosphere. Electrochemical treatment was performed by anodic polarization at +750 mV versus SCE in 1N H2SO4 for 2 h. The alloys spontaneously passivate under the formation of a barrier-type film upon immersion in the acid solution due to the high passivation tendency of the valve-metal components.