X-ray diffraction study of a Bi4Ge3O12 crystal

✍ Scribed by T.I. Milenov; P.M. Rafailov; R. Petrova; Yu.F. Kargin; M.M. Gospodinov

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 857 KB
• Volume: 138
• Category: Article
• ISSN: 0921-5107
• DOI: 10.1016/j.mseb.2007.01.001

✦ Synopsis

A Czochralski grown Bi 4 Ge 3 O 12 crystal plate of (BGO) was examined by several X-ray diffraction methods. The crystal structure, lattice parameter and the atomic positions were determined by single crystal X-ray diffractometry. The X-ray diffraction double crystal traverse topography (XRDT) images reveal that the core area of the crystal is strained and occupied by dislocations with different Burgers vectors (but mainly b = 0 0 1 ), lines lying along the growth axis [0 1 1] and density that does not exceed 20-30 cm -2 . It was established that the almost entire crystal surface (without the core area) is occupied by two-dimensional defects, probably some form of stacking faults. Several Lauegrams were taken from different parts of the plate that showed no presence of any two-dimensional defects. The X-ray microprobe analysis of all three-dimensional defects on the crystal surface showed that all they were probably gas bubbles and a GeO 2 -precipitate was detected in one case only.