About the possible observation and magnetic characterization of amorphous Ni

Recently Rojo et al. (Phys. Rev. Lett. 76 (1996) 4833; Phys. Rev. B 56 (1997) 5039) have reported the observation and magnetic characterization of Ni in amorphous state, as an intermediate phase that is produced during the crystallization process of the Ni 80B 20 metallic glass. In the present work we have reproduced the main experiments which gave rise to this observation, as well as carried out new ones. Our results are in contradiction with those obtained by Rojo et al. and raise doubts as to whether they observed amorphous Ni in their experiments and, of course, their magnetic characterization.