A nanoglass is a new type of metallic glasses that can by synthesized by consolidating glassy powder. Nanoglasses consist of glassy grains connected by glass-glass interfaces. Glass-glass interfaces are characterized by a defective short-range order and an excess free volume. Similar to pre-deformed metallic glasses where pre-induced shear bands act as a softer phase with lower barriers for shear band nucleation, the glass-glass interfaces introduce strain concentrations which act as initiation sites for shear bands. We studied the deformation behavior of nanoglasses by tuning the size and compositions of glassy grains . All these results indicated that glass-glass interfaces are soft heterogeneities which improve the mechanical properties of bulk metallic glasses.
 D. Sopu, and K. Albe, Beilstein J. Nanotech. 6 (2015) 537-545 URL