Strain contrast in low-energy electron microscopy was obtained by dark-field imaging of the strain-sensitive variants of a surface reconstruction. This was used to make visible the strain fields of dislocations in Nb(011) thin single-crystal films. The strain field symmetries revealed the dislocation Burgers vectors and identify the existence of a/2[111] and a[100] Burgers vectors for threading dislocations in these epitaxial materials. The contrast also allows interfacial and screw dislocations to be imaged.

Studies of Threading Dislocations in Nb(011) Films. R.S.Appleton, W.Swiech,