Detailed structural and magnetic characterization was carried out on nominally amorphous melt-spun ribbon based on the composition Nd 60 Fe 30− x Al 10+ x to pursue the origins of its anomalously large coercivity values. The combined structural and magnetic analyses point to the existence of antiferromagnetic motes within the melt-spun ribbon. The average diameter of these motes is 1.2±0.5nm and their crystal structure is related to the Nd 6 Fe 13− x Al 1+ x , δ-phase structure, which under equilibrium conditions is the primary solidification phase near the Nd 60 Fe 30 Al 10 composition. These motes are hypothesized to strongly couple to the ferromagnetic matrix phase in an “exchange-bias”-type manner and confer extremely high values of coercivity at low temperature. The composition dependence of the δ-phase Néel temperature is reflected in the composition dependence of the onset of large values of coercivity in the melt spun ribbons. The results obtained from melt-spun ribbons are compared to those obtained from a 10gm drop-cast ingot 6mm diameter of the same nominal composition and are found to be internally consistent. Delineation of the solidification pathway in the vicinity of the composition RE 60 Fe 30 Al 10 provides a sound physical explanation of the variety of microstructures and associated variety of magnetic behavior found in cast and melt-spun forms of this material.