Relaxation behavior on high frequency profile in strong/fragile metallic glass-forming systems

The coupling of the slow beta-relaxation and the prominent a relaxations in various metallic glass-forming systems with different fragilities is studied. The coupling of the alpha- and slow beta-relaxation depends on the fragility of the metallic liquids and causes an obvious violation of the time-temperature superposition principle in rather strong metallic glass-forming liquids. The results are qualitatively discussed based on the microstructural characteristic of the BMGs consisting of the dense-packing regions and loose-packing regions. (C) 2010 Elsevier B.V. All rights reserved.