Investigation of synthetic cylindrite-microstructures

The mineral cylindrite belongs to the group of sulphosalts and has a natural stoichiometry close to FeSn4Pb3Sb2S14. Ferromagnetism has been detected in the natural mineral. Due to this property and its semiconducting properties with a narrow band gap of app. 0.65 eV, cylindrite is interesting for new technical applications. In this work, cylindrite-microstructures produced by chemical vapour transport (CVT) have been investigated by ion beam analysis. The analysis was performed at the LIPSION laboratory utilising a proton microbeam. We determined the composition of the cylindrite-microstructures using μRBS and μPIXE in order to compare the composition of the natural and the synthetically produced samples. The investigated microstructures had a width of a few micrometer and a high aspect ratio. The cross-sections were either circular or square, thin platelets were also investigated. For this application it was necessary to focus the proton beam to below 1 μm and to develop a data analysis package for RBS on microstructures. We conclude that it is possible to analyse these non-planar microstructures quantitatively using microbeams. Furthermore, these preliminary results show that cylindrite-microstructures have different nominal compositions compared to larger cylindrite structures