Rietveld refinement of the semiconducting system Bi2-xFexTe3 from X-ray powder diffraction

The semiconducting system Bi2-xFexTe3 (X = 0.0, 0.02, 0.04 and 0.08) was synthesized at 1000 degrees C for 30 h. The scanning electron microscope (SEM) image reveals the tendency of the Bi2-xFexTe3 system to form a sheet structure with more pronounced alignment and to enhance the formation of some microstructure tubes. The structure of the system under study was refined on the basis of X-ray powder diffraction data using the Rietveld method. The analysis revealed the complete miscibility of Fe in the Bi2Te3 matrix and hence the formation of single phase. The system crystallizes in the space group R-3m [166]. The lattice parameters and the unit cell size slightly change by the incorporation of Fe. The refinement of instrumental and structural parameters led to reliable values for the R-B, R-F and Chi(2). (c) 2007 Elsevier Ltd. All rights reserved.