Silica structural changes induced by thermal treatment or ionic implantation as probed by IR reflectance spectroscopy

Abstract

Fourier transformed infrared microreflectance spectroscopy is used to probe and compare the consequences of thermal quenching or ionic implantation on the structure of silica. A linear change in the main structural feature associated with Si–O–Si vibration with fictive temperature (Tf) is observed up to Tf=1400 °C. Ionic implantation is shown to shift the frequency of the main IR Si–O–Si vibration toward much lower wavenumbers, for all deposited energies, indicating that a comparison can be drawn between fictive temperature and irradiation effects. Extrapolating the linear changes in the IR structural bands obtained as a function of Tf for the implanted samples, we show that two structural (νTO) and (νB) contributions are not affected by ionic implantation, as they would be by a unique very high Tf. In the case of ionic implantation, we also evidence the development of some specific structural contributions indicating a depolymerization of silica network.