Bulk samples of this metallic glass-forming alloy were studied at temperatures ranging from 530 and 710K; a range which extended by 85K into the supercooled liquid state of the alloy. A change in the temperature dependence of the data was observed at the glass transition temperature; with the diffusivity increasing more quickly with temperature above the transition than below it (figure 11). The data for the supercooled liquid could be described by using a modified Arrhenius expression that was based upon a diffusion mechanism. A comparison with viscosity data in the supercooled liquid state of the alloy revealed a breakdown of the Stokes-Einstein relationship; thus indicating that a cooperative diffusion mechanism operated in the supercooled liquid state of the alloy.

U.Geyer, W.L.Johnson, S.Schneider, Y.Qiu, T.A.Tombrello, M.P.Macht: Applied Physics Letters, 1996, 69[17], 2492-4