High-Resolution Electron Microscopic Studies of CS Structure in Reduced WO3Thin Crystals

The crystallographic shear (CS) structure in reduced WO3crystals grown in vacuum-deposited amorphous films by electron heating, is investigated with a 200 kV electron microscope and by computer simulation. A new type of ordered (100) CS structure with the shear vector [101]a/4 is found in the reduced WnO3n-1crystals with the (001) surface. Images which may be associated with ordered (100) oxygen vacancy walls and imperfect (100) CS planes are observed. The most reduced crystal observed is W2O5(n=2).