Parallel stacking faults on (010) planes were frequently observed in hot-pressed

Y2Si2O7. A combination of conventional dark-field imaging and high-resolution

transmission electron microscopy was used to investigate the structure of these

faults. It was found that they consisted of the repeat of one layer of the two-layer γ-

Y2Si2O7 structure with an associated in-plane rigid body displacement. The

resulting structure was confirmed by image simulation of high-resolution images

from two perpendicular projections. A model for the formation of the stacking

faults was proposed as a consequence of a transformation from β-Y2Si2O7 to γ-

Y2Si2O7 in the hot pressing.

Structure and Possible Origins of Stacking Faults in Gamma-Yttrium Disilicate.

I.MacLaren, G.Richter: Philosophical Magazine, 2009, 89[2], 169-81