A prediction was made of the formation of surface defects in a thin amorphous silica layer, during the relaxation of externally imposed stresses and strains, based upon extensive ab initio molecular dynamics calculations. The calculations showed that the application of a biaxial compressive stress led to the creation of edge-sharing tetrahedron and/or silanone defects at the silica surface. This facilitated strain-relief, with irreversible structural changes in the silica layer. A possible correlation was identified between the predicted formation of surface defects and the observed enhanced surface reactivity of amorphous silica under compressive strain conditions.

Strain-Induced Formation of Surface Defects in Amorphous Silica - a Theoretical Prediction. C.L.Kuo, S.Lee, G.S.Hwang: Physical Review Letters, 2008, 100[7], 076104