Effects of yttrium on the formation and magnetic properties of bulk metallic glassy (Fe, Co)-B-Si-Nb alloys

Abstract

The bulk metallic glassy (BMG) rods of [(Fe_0.5Co_0.5)_0.72B_0.192Si_0.048Nb_0.04]_100−xY _x (x=0−6) and [(Fe _xCo_1−x)_0.72B_0.192Si_0.048Nb_0.04]₉₆Y₄ (x=0.5−0.8) were prepared by copper mold casting. The structure, thermal stability, and magnetic properties of the samples were studied by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and vibrating sample magnetometer (VSM). Adding 1at% to 6at% of yttrium, the bulk glassy alloy rods of [(Fe_0.5Co_0.5)_0.72B_0.192Si_0.048Nb_0.04]_100−xY _x (x=0−6) with the diameter of 3 mm were not formed, and the sample with 4at% of yttrium showed less crystalline phase than others. When the Fe/Co atomic ratio was between 5:5 and 7:3, the bulk glassy alloy rods of [(Fe_1−xCo _x)_0.72B_0.192Si_0.048Nb_0.04]₉₆Y₄ (x=0.5−0.8) with the diameter of 2 mm were fabricated. In the (Fe, Co)-B-Si-Nb-Y BMGs, when the Fe content increased, the thermal stability, the supercooled liquid region, and the glass-forming ability (GFA) decreased, but the saturation magnetization (M _s) increased.

Keywords

bulk metallic glass / glass-forming ability / yttrium / magnetic properties

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