Varying kinetic stability, icosahedral ordering, and mechanical properties of a model Zr-Cu-Al metallic glass by sputtering

Abstract

${\mathrm{Zr}}_{65}{\mathrm{Cu}}_{27.5}{\mathrm{Al}}_{7.5}$ metallic glass thin films with widely varying kinetic stability as a function of deposition rate were synthesized by single-target direct current magnetron sputtering. Fluctuation electron microscopy and angular correlations in coherent electron nanodiffraction show that glasses with increased stability have increased nanoscale structural order, particularly of icosahedral character. The most kinetically stable film's reduced modulus was 22% higher than a glass of the same composition rapidly quenched from the liquid, consistent with increased density and improved thermodynamic stability. These results suggest that enhanced nanoscale icosahedral order contributes both to the kinetic stability of the glass and its resistance to mechanical deformation.