Thermal, magnetic and magnetocaloric properties of Fe80−xMxB10Zr9Cu1 (M = Ni, Ta; x = 0, 3, 5) amorphous alloys

Abstract

The thermal, magnetic and magnetocaloric properties of amorphous Fe80−xMxB10Zr9Cu1 (M=Ni or Ta; x=0, 3, and 5) alloys were investigated. Both Ni and Ta additions reduce the crystallization temperature (Tx1). The Curie temperature (TC) can be increased or decreased by the addition of Ni or Ta, respectively. The saturation magnetization (MS) decreases from 126.5Am2kg−1 (without Ni or Ta) to 83.5 or 29.4Am2kg−1 for 5at.% Ni or Ta addition, respectively. The maximum magnetic entropy change (−ΔSM)max of the amorphous alloys shows a decline trend with increasing Ni or Ta content. Under an applied magnetic field change of 5T, the (−ΔSM)max for Fe80−xNixB10Zr9Cu1 with x=0, 3, and 5 are 3.28, 3.13, and 3.04Jkg−1K−1, respectively, while the (−ΔSM)max for Fe80−xTaxB10Zr9Cu1 with x=3 and 5 are 2.84 and 2.03Jkg−1K−1, respectively. The values of refrigeration capacity (RC) for the experimental alloys are higher than those of Fe80−xGdxCr8B12 (x=5 and 10) alloys. In particular, the RC for the Fe80−xNixB10Zr9Cu1 (x=3 and 5) and Fe77Ta3B10Zr9Cu1 alloys are comparable to that of the well-known MCM crystalline Gd5Si2Ge2. With large RC, negligible hysteresis and good thermal stability, these alloys can be used as the high temperature magnetic refrigerants working in the temperature range of 330–410K.