Tracking the subsurface path of dislocations in GaN using scanning tunneling microscopy

Abstract

A methodology for the determination of the subsurface line direction of dislocations using scanning tunneling microscopy (STM) images is presented. The depth of the dislocation core is derived from an analysis of the displacement field measured by STM. The methodology is illustrated for dislocations at GaN(10 10) cleavage surfaces. It is found that the dislocation line bends toward the surface, changing from predominantly edge-type to more screw-type character, when approaching the intersection point. Simultaneously, the total displacement detectable at the surface increases due to a preferred relaxation towards the surface. V C 2015 AIP Publishing LLC.

Observation of Hidden Parts of Dislocation Loops in Thin Pb Films by Means of Scanning Tunneling Spectroscopy

“…Numerical modeling of thin-film structures and nanostructures with screw dislocations and periodic network of dislocations are presented in refs − . Surely, linear defects like dislocations and disclinations at the surface can be easily visualized by scanning tunneling microscopy − or by atomic-force microscopy. − The hidden dislocation lines inside metallic films can be imaged by means of scanning and transmission electron microscopy. − However, both atomic force microscopy and electron microscopy do not allow the testing of local electronic properties (such as local current–voltage dependence, value of superconducting gap, etc). It seems interesting to develop experimental methods based on the tunneling interferometry for deeper analysis of local electronic properties in regions with internal stress near the dislocation lines.…”

Method combining scanning tunneling microscopy and atom probe tomography for observing inside of materials

“…So far, the only method for this purpose is probably cleavage, which has been applied to semiconductors, layered materials and some brittle metals for the preparation of XSTM samples. [3][4][5][6][7][8][9][10] However, this method can be applied to a very limited number of materials.…”