Study of structural, optical and transport properties of semiconducting Fe2O3-PbO-B2O3 glasses

Semiconducting oxide glasses of compositions xFe(2)O(3 center dot)(40-x)PbO(center dot)60B(2)O(3) have been prepared by the standard melt-quenching technique over the range 0 <= x <= 20) (x is in mol%). The amorphous nature of the samples was ascertained using X-ray diffraction patterns. The structural changes in these glasses have been investigated by IR spectroscopy. The values of characteristic glass transition temperature (T-g) have been found from differential scanning calorimetry (DSC) traces and corresponding specific heat capacity (C-p) was also estimated. It is found that the density of these glasses decreases but glass transition temperature increases as Fe2O3 content is increased. The change in both the density and molar volume was discussed in terms of the structural modifications that take place in the glass matrix upon replacing PbO by Fe2O3 The dc conductivity of these samples was measured in the temperature range 473-623 K. In this temperature range, the dc conductivity increases from 10(-9) to 10(-4) S/m with increasing Fe2O3 content due to electron hopping from Fe(II) to Fe(III) ions. The values of the theoretical optical basicity of these glasses have also been determined.