Electron Microscopic Study of the Structure Defects and Their Interactions in Niobiumditelluride

The structure of niobiumditelluride is analysed in terms of its deviations from the cadmiumiodide structure. From this structure model several types of defects are predicted: three types of domain boundaries, two types of antiphase boundaries, and dislocations having a particular fine structure. Direct evidence for the existence of these defects is provided by a series of observations with the electron microscope. The domain configurations as well as the dislocation fine structure are analysed in detail and an excellent agreement is found between the theoretical predictions and the experimental results. Also the interaction between the dislocation multiribbons and the domain boundaries is studied. The behaviour of the dislocations fully supports the structural model.