Effects of passing electric current on the elastic property of amorphous Cu50Zr50 and Cu50Ti50

Abstract

For both amorphous Cu50Zr50 and Cu50Ti50, the dynamic Young's modulus M was found to increase under passing electric d.c.-current (PEC) with the current density id below 5 × 103 A/cm2, suggesting that PEC induces internal stress. The id dependence of M observed at low strain amplitude εt was found to be identical to the εt dependence of M without PEC after scaling between id and εt, giving Z* in the order of 105, where Z* is the apparent charge number measuring the electromigration force (EM-force) under PEC. We surmise that such a large Z* reflects the concentration of EM-force through the collective motion of many atoms, Z* = z*ξ, for ξ atoms with the charge number z* per atom. Application of this view to the observed effect of annealing on Z* gives ξ as several hundreds in the as-quenched state. Based on the present results, the effects of PEC on the structural relaxation and crystallization processes reported are also discussed.