High temperature deformation in a lanthanum based bulk metallic glass showing a pronounced secondary relaxation

The deformation at high temperature of a La60Ni15Al25 bulk metallic glass has been investigated. In the experimental domain in which homogeneous deformation could be obtained, activation energies in agreement with what is usually measured for metallic glasses with similar glass transition temperatures were identified but particularly large values of activation volumes were measured. Such values of activation volumes were attributed to the pronounced secondary relaxation displayed by the investigated glass, suggesting the existence of structural heterogeneities in the microstructure.