A HRTEM STUDY OF THE CRYSTAL-STRUCTURE OF ZR4CO4GE7

A study of the crystal structure of the Zr4Co4Ge7 (V-phase) intermetal lic compound was carried out using electron microscopic techniques. Re sults of electron diffraction (ED) analysis show that Zr4Co4Ge7 has a body-centered tetragonal structure with space group 14/mmm. Images tak en by high-resolution transmission electron microscopy (HRTEM) reveale d the structure at the atomic level. Large bright spots in the [001] z one HREM image represent Ge-centered square antiprism columns, and the eight small bright spots around them represent Co-centred octahedron columns. Good agreement between the observed and simulated images was obtained confirming the results proposed earlier based on X-ray diffra ction analysis.