Impact of Compositional variation of amorphous phase coercivity of Nd60Fe30Al10 alloy

The coercivity of Nd-Fe-Al amorphous ferromagnetic materials originates from the combination of magnetic interaction and strong pinning of domain walls. Using Nd60Fe30Al10 alloys made under three cooling rates, we discovered an important microstructure parameter that can be used to strengthen interaction and pinning. By tuning the variations of composition differences between Nd-rich and Fe-rich amorphous regions, we enhanced the magnetic interaction and and appear to passively enhance increased the maximum restoring force per pin of Nd nanocrystals (with size less than 30 nm embedded in amorphous matrix). We were, however, not able to change pinning force by changing the grain morphology and the size of Nd nanocrystals (<30 nm).