CHOICE OF Bi2223 UNIT CELL FOR TEXTURE STUDIES USING ORIENTATION DETERMINATION IN THE SCANNING ELECTRON MICROSCOPE
Abstract
Existing proposals for the crystal structure of the high temperature superconducting Bi2Sr2Ca2Cu3O7-x (Bi2223) phase have been reviewed. For the purpose of automated orientation determination in the scanning electron microscope using electron backscatter pattern (EBSP) analysis, a new crystal structure is proposed, where the unit cell is assumed to be tetragonal with P4/mmm point-group symmetry. Simulated EBSP images corresponding to the various unit cells exhibit significant differences, confirming the importance of choosing the correct unit-cell information. The suitability of various choices of the unit cell for automated orientation determination using EBSP analysis has been investigated using experimental data. The newly proposed unit cell is superior to the other unit cells for each of the criteria used to assess the indexing ability.
