Chapter 1 - Optical absorption, luminescence, and ESR spectral properties of point defects in silica

Abstract

This chapter is divided into two parts: (1) In the introductory part, it describes the problems of point defects in a-SiO2, and (2) in the second part it discusses the experimental results. This chapter focuses on the Oxygen-Deficient Centers (ODCs) species in silica. This chapter investigates the ODC defects in a-SiO2 through their optical absorption, photoluminescence, and electron spin resonance activities. The effects of γ-ray irradiation are also investigated to evidence their ability to generate or transform structural defects. The aim of this chapter is to understand the optical activity of such defects to help in the characterization of their structure. The properties of point defects in a wide variety of both natural and synthetic silica types of commercial origin are investigated in the chapter. This chapter outlines the role of structural and dynamic properties of the vitreous matrix in determining the observed spectral properties of different centers. It deals with the theoretical aspects of the mechanism that are able to influence the fine structure of the spectral band profiles of point defects in interaction with the glassy matrix.