Moessbauer and X-ray studies on the existence of a cubic stannite phase in natural ores

In a study of natural stannite (GDR) samples (Cu2FeSnS4) of the Zinnwald deposit 57Fe Moessbauer patterns were found different from those measured by other authors for stannite samples. In addition to the usual doublet with a quadrupole splitting of 2.88 +- 0.02 mm/sec with respect to a 57Co-Pt source and a line width of 0.25 +- 0.04 mm/sec, a second doublet of lower intensity was found with a quadrupole splitting of 1.01 -+ 0.04 mm/sec, an isomer shift of -0.09 +-0.04 mm/sec and a line width of 0.46 +- 0.07 mm/sec. In the investigation a chemical analysis, Moessbauer spectrometry, X-ray diffraction and DTA were used. The measurement results indicate that the Zinnwald stannite contains a cubic modification in addition to the tetragonal phase. (Z.S.)