Influence of La and Ce additions on the magnetocaloric effect of Fe–B–Cr-based amorphous alloys

Abstract

The magnetic entropy change (ΔSM), temperature of peak ΔSM (Tpk) and refrigerant capacity (RC) in Fe(RE)80B12Cr8 (RE = La, Ce, or Gd) alloys were studied. Increasing La, Ce, and Gd content led to relatively constant, decrease, and increase in Tpk, respectively. Both the phenomenologically constructed universal curve for ΔSM and field dependence power laws demonstrated that these alloys exhibited similar critical exponents at Curie temperature. With 5% Ce added to Fe80B12Cr8, Tpk could be tuned near room temperature with relatively constant peak ΔSM. Fe79B12Cr8La1 exhibited enhanced RC compared to Gd5Si2Ge1.9Fe0.1. The tunable Tpk and enhanced RC are needed in active magnetic regenerators.