Glass-liquid transition in a less-stable metallic glass

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A stable metallic glass, SMG, is often viewed as an amorphous alloy exhibiting a reversible glassliquid transition. Here we show experimentally that even in a less-stable metallic glass, LMG, which is prepared only by rapid melt quenching and promptly crystallized without glass transition at the ordinary heating rate, sufficiently rapid heating exposes the glassliquid transition by suppressing crystallization. The experimental glass transition Tg and crystallization Tx temperatures were plotted as a function of heating rate , for Pd42.5Ni7.5Cu30P20 of SMG and for Zr70Ni30 of LMG. Two extrapolated curves, Tg–log and Tx–log , intersect at a quite small , e.g., ~10–4 °C/min, for SMG, whereas their intersection occurs at a large , e.g., ~10 °C/min, for LMG. Such a large that is comparable to conventional heating rates makes it difficult to observe the reversible glass transition in LMG, and reflects low thermal stability of the glassy state.