FAST RELAXATION IN A METASTABLE METALLIC MELT

The recent discovery of bulk metallic glasses opened the possibility t o study their metastable melt far above the glass transition temperatu re. Alloying Fe-57 to the glass ZrTiCuNiBe we succeeded in performing Mossbauer absorption experiments up to 70 K above T-g. While quasi-ela stic broadening from structural relaxation was not detected, the Lamb- Mossbauer factor shows an anomalous decrease. From previous neutron sp ectroscopy, we exclude phonon anharmonicity as a cause. The missing el astic intensity can therefore be ascribed to a fast relaxation process . This is a first indication that the glass transition scenario predic ted by mode coupling theory and observed in a number of different syst ems also applies to metallic alloys.