Rare-earth—gallium—iron glasses. II. Anomalous magnetic hysteresis in alloys based on Pr, Nd, and Sm

Giant magnetic coercivity is reported in several metallic glasses of the form (R₈₀G₂₀)_100-xFeₓ where R represents Pr, Nd, or Sm, G represents Ga or Au, and 15≤x≤30. An unusual temperature variation of the coercive field is observed showing peaks at intermediate temperatures ({}90 K). In contrast to similar glasses based on heavy rare-earth metals, these glasses exhibit significant chemical short-range order and even phase separation as is shown by the M\"ossbauer effect and other measurements. The results are consistent with a recent theory which predicts that large coercivity can result from the presence of site-to-site variations in magnetic properties.