Electrophysical properties of EuA25X46 type compounds

Electrophysical properties of the compounds EuSb2S4(Se4,Te4) and EuBi2Te4 have been studied. Semiconducting properties of thio- and selenoantimonites (bismutites) of europium have been detected and the width of the forbidden band for these compounds has been determined. The characteristic conductivity region for EuSb2S4 is above 820 deg K, for EuSb2Te4 above 730 deg K, for EuSb2Se4 above 780 deg K, and for EuBi2Te4 above 760 deg K. Electroconductivity of the compounds at 20 deg C increases with an average atomic weight of the components of the compounds, the width of the forbidden band and the coefficient of thermo -e.m.f. simultaneously decreasing