NMR studies of metal and metalloid site hyperfine field distributions in magnetically ordered amorphous alloys

We report spin-echo NMR studies of hyperfine field (hf) distributions in a number of magnetically ordered Fe and Co-based amorphous systems. These distributions are broad and often complex due to the overlap of NMR signals arising from both metal and metalloid atoms. We show that by using isotopic substitutions it is possible to separate the metal and metalloid site hyperfine field distributions in Fe-based systems. In many instances it is possible to compare these results with those obtained on related crystalline compounds to identify the environments responsible for the hf distributions observed in the amorphous phase. We also present studies of annealing and cold working on electrodeposited amorphous Co-P samples. Local environmental models provide a good description of our results.