PbO-SiO<SUB>2</SUB>-Al<SUB>2</SUB>O<SUB>3</SUB>とNa<SUB>2</SUB>O-SiO<SUB>2</SUB>-Al<SUB>2</SUB>O<SUB>3</SUB>系ガラスの赤外線吸収スペクトルに関する研究

Abstract

Observation on the change of shape of silica anions in molten silicates resulting from the addition of Al2O3 as a third element should be of great importance in order to understand the constitution of molten slag. In the present studies, the measurements of infrared absorption spectra have been carried out for a purpose of finding the effect of Al2O3 on the lead and sodium silicate melts.In PbO-SiO2-Al2O3 and Na2O-SiO2-Al2O3 systems, it was found that the peak of an absorption band due to the stretching vibration (ν3) of silicon-oxygen tetrahedron showed a shift to one of about 1020, 990 or 970 cm−1 in wave number with increasing Al2O3 content in the silicate. For example, in the case of Al2O3 addition to the sodium silicate containing 33.3 mol%Na2O, the spectrum of the original glass consists of two bands, with absorption peaks at about 1070 and 950 cm−1. The peak at 1070 cm−1 shifted to the lower frequency side, while the peak at 950 cm−1 shifted to the higher frequency side with increasing Al2O3 content, and beyond 15 mol%Al2O3 one absorption peak was observed at approximately 990 cm−1 instead of two absorption bands. The absorption band due to the vibration of AlO4 tetrahedron in glassy silicate was observed at approximately 700∼730 cm−1, the intensity of which apparently increased with increasing Al2O3 content in the silicates.