Infrared Absorption by Small Amorphous Quartz Spheres

Optical constants for fused quartz were determined from 1400 cm(-1) to 400 cm(-1). Three absorption bands were observed in the infrared for amorphous quartz powder dispersed in KBr. These same bands, somewhat altered in shape and in peak position, were seen in amorphous SiO(2) smoke particles in air. Two of these bands were determined to be due to surface modes. Measurements agreed well with calculated peak positions and relative peak heights, but were broader and lower than those predicted by theory. The observed broadening could not be attributed to the size or shape of the individual particles.