Enhancement of magnetocaloric effect in B-rich FeZrBCu amorphous alloys

Abstract Magnetic properties and magnetocaloric effect were studied in the Fe 92 − x Zr 7 B x Cu 1 amorphous alloy series ( x  = 0–23 at.%). Enhancement of the magnetocaloric effect was observed in the B-rich side ( x  > 15 at.%) which correlates well with the anomalous increase of the saturation magnetic moment per Fe atom in this concentration range. Research into Fe 2 (B 1 − y ETM y ) amorphous alloys (ETM = Zr, Nb, Ti and V; y  = 0–0.55 atomic fraction for Zr and to 0.25 atomic fraction for the rest) reveals an unexpected increase of the iron magnetic moment when early transition metals are substituted for B up to y  = 0.1–0.25 atomic fraction. This behavior is attributed to the highly attractive B–ETM interaction. Similar mechanism is thought to explain the anomalous increase of the iron magnetic moment and hence the magnetocaloric effect in the boron-rich Fe 1 − x Zr 7 B x Cu 1 amorphous alloys. Universal scaling of the magnetic entropy change curves is also used to detect differences between Fe 92 − x Zr 7 B x Cu 1 alloys.