Structural changes induced by microalloying in Cu46Zr47-xAl7Gdx metallic glasses

Al-27 nuclear magnetic resonance spectroscopy was used to probe the atomic-scale structural evolution in Cu46Zr47-xAl7Gdx (x = 0, 1, 5) glassy alloys with minor Gd addition. It was found that the local symmetry of atomic clusters around Al atoms is the closest to being spherical at 1 at.% Gd addition. Interestingly, this also corresponds to the Gd content for which the glass-forming ability (GFA) reaches a maximum, suggesting that the GFA of these glassy alloys may be dominated by their local geometric structure. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.