The effect of Cu on the properties of Nd-based bulk metallic glasses

Diamagnetic Cu was added into hard magnetic Nd–Fe–Al bulk metallic glass in the present study. The effects on the magnetic properties and glass-forming ability (GFA) were assessed using vibrating sample magnetometer and thermal expansion method. The results show that Nd60Fe20Cu10Al10 have highest GFA and the coercivity is high up to 313 kA/m as well. The former was attributed to the more negative mixing heat between Cu and Nd and the latter was caused by the emergence of ferromagnetic Fe-rich phase or cluster. Given a further increasing on copper, a sharp reduction happens to magnetic properties. This reduction can be attributed to the emergency of soft magnetic and non-magnetic crystalline phases (NdCu5, Nd-rich phase, δ phase and Nd phase).