Scientific article
Open access

Mixed PbFBr1-xIx crystals: structural and spectroscopic investigations

Published inJournal of physics. Condensed matter, vol. 19, no. 3, 36214
Publication date2007

Mixed single PbFBr1−xIx crystals have been prepared. X-ray powder diffraction structure determinations show that all samples crystallize with the matlockite structure. However, the single crystal structure of PbFBr0.5I0.5 involves not only fractional occupation of one site corresponding to the stoichiometry, but also split positions of the Pb2+ ion. Raman spectra reveal the presence of new additional bands with respect to PbFBr and PbFI. DFT calculations of lattice vibrations for PbFI show good agreement with experimental spectra. The calculated phonon dispersion curve suggests that for the mixed crystals the centre of inversion is conserved locally. These combined results suggest the presence of domains with ordered F–Pb–Br–Br–Pb–F and F–Pb–I–I–Pb–F layers in the mixed crystals. Calculations on PbFBr0.5I0.5 show that this suggested structure is more stable than the structure consisting of the F–Pb–Br–I–Pb–F arrangement.

Research group
Citation (ISO format)
HAGEMANN, Hans-Rudolf et al. Mixed PbFBr1-xIx crystals: structural and spectroscopic investigations. In: Journal of physics. Condensed matter, 2007, vol. 19, n° 3, p. 36214. doi: 10.1088/0953-8984/19/3/036214
Main files (1)
Article (Published version)
ISSN of the journal0953-8984

Technical informations

Creation10/02/2009 3:18:46 PM
First validation10/02/2009 3:18:46 PM
Update time03/14/2023 3:15:35 PM
Status update03/14/2023 3:15:35 PM
Last indexation01/15/2024 7:03:42 PM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack