  Studying the primary {\alpha}- and secondary {\beta}-relaxation process has
contributed significantly to the understanding of the structure and rheology of
metallic glasses. In this letter, we report on a third relaxation mechanism
indicated by a maximum in the loss modulus at low temperatures, which we term
{\gamma}-relaxation. Contrary to the {\alpha}- and {\beta}-relaxation
mechanisms, this irreversible, low energy excitation causes a macroscopic
rejuvenation, which we assign to non-affine atomic rearrangements in the matrix
that are driven by thermal stresses during cooling. Observed in three different
glassy alloys, the low temperature relaxation is identified as a general
process in metallic glasses.

Materials Science;Disordered Systems and Neural Networks