Analysis of twin boundaries using the electron backscatter diffraction (EBSD) technique

The twin structure of various bulk, high-Tc superconductors is analysed using the electron backscatter diffraction (EBSD) technique. The high image quality of the Kikuchi patterns recorded enables a high spatial resolution of the order of 40 nm to be achieved; thus details of the twin patterns can be measured in straightforward way. As samples, we employed both melt-textured samples and single crystals of NdBa2Cu3Oy (NdBCO) and (Nd0.33Eu0.33Gd0.33)Ba2Cu3Oy (NEG). Both types of samples show a well-developed twin structure, where several details can be observed using the so-called crystal direction (CD) mappings, which provide orientation maps using colours close to the pole directions. These results are compared to theoretical descriptions found in the literature.