CONDUCTIVE SNO2/SB POWDER - PREPARATION AND OPTICAL-PROPERTIES

Preparation of an SnO2 semiconducting powder doped with antimony (x = 2.38 mol %) was achieved by co-precipitation. The unit cell parameters of the doped SnO2 powders were measured and their changes with dopant concentration were determined. Four-point sheet resistance measurements, together with optical and infrared spectra of the powder were taken in order to obtain a highly-conducting, low-emitting powder which could be used for antistatic paint preparation. Evolution of the phonon bands corresponding to Sn-O stretching modes as a function of dopant concentration were followed, and a model calculation based on an extended four-parametric Kurosawa relation was applied to the reflection spectra of differently doped powders. It was found that the frequency of the plasma oscillations shifts with dopant concentration, and the intensity of the reflectivity peaks was correlated with plasmon-phonon interactions. An additional negative reflection peak in the range 1100 to 1200 cm-1 was found in the reflection spectra of highly doped powders and was attributed to the coupled modes between the plasma oscillations and one of the phonon combinational or overtone modes of SnO2.