Diffuse Reflectance Spectra of Some Compounds of Elements of IV a Group

Abstract

Diffuse reflectance spectra of lead halides, lead oxide, and stannic oxide have been studied in the region 1.2–6.20 eV. Four bands at 2.52, 3.10, 3.90, and 5.93 eV have been observed in pure samples of lead iodide while only three bands have been observed at 3.48, 4.08, and 5.17 eV and 4.30, 4.72 and, 5.90 eV, respectively, in samples of lead bromide and lead chloride. The assignment of these bands has been discussed in the light of band structure of lead halides. Two bands at 3.54 and 5.61 eV and one band at 5.64 eV have been observed in pure samples of lead oxide and stannic oxide, respectively. These bands have been assigned to band-to-band transitions.