Crystallization, Phase Decomposition, and Magnetism of the Novel As-Quenched Mn–Si–B-Based Amorphous Ribbons.

The effects of iron, copper, and niobium alloying additions on crystallization, phase transformation, and magnetic properties of Mn–Si–B-based amorphous ribbons were studied by X-ray diffraction (XRD), differential scanning calorimeter (DSC), and physical property measurement system (PPMS). The DSC results show that Mn₇₈Si₁₃B₉ amorphous sample presents one-stage crystallization reaction. When added the alloying elements of iron, copper, and niobium into Mn–Si–B alloy system, the alloys still exhibit one-stage crystallization behaviors, but the crystallization temperature (T_x) has changed. The alloying addition of iron in Mn–Si–B alloy makes a decrease in T_x, while making further microalloying additions of copper and niobium in Mn–Fe–Si–B alloy the T_x of the alloy elevates significantly. For Mn₇₈Si₁₃B₉, Mn₆₈Fe₁₀Si₁₃B₉, and Mn₆₄Fe₁₀Si₁₃B₉Cu₁Nb₃ alloys, the crystallization of amorphous phase simultaneously forms α-Mn(Si), Mn₆Si, and Mn₂B phases upon heating above the glass transition temperature. Besides, the thermal-magnetization M(T) curves confirm that the amorphous Mn₇₈Si₁₃B₉ and Mn₆₈Fe₁₀Si₁₃B₉ samples exhibit a characteristic spin-glass behavior. The spin-glass freezing temperatures of them are about 20 ~ 22 K. [ABSTRACT FROM AUTHOR]