Transient stress evolution and crystallization in laser-irradiated amorphous titania sol-gel films

Gregory J. Exarhos; Nancy J. Hess; Susanne Wood

doi:10.1117/12.60094

29 July 1992 Transient stress evolution and crystallization in laser-irradiated amorphous titania sol-gel films

Gregory J. Exarhos, Nancy J. Hess, Susanne Wood

Proceedings Volume 1624, Laser-Induced Damage in Optical Materials: 1991; (1992) https://doi.org/10.1117/12.60094
Event: Laser-Induced Damage in Optical Materials: 1991, 1991, Boulder, CO, United States

Abstract

Amorphous Ti02 sol-gel films are irreversibly transformed to a crystalline anatase phase when heated to temperatures in excess of 575 K or subjected to intense pulsed or CW laser irradiation. The laser-induced transformation is initiated as a result of impurity absorption and subsequent heating, and results in densification and relative changes in compressive stress of the film. Isothermally annealed films exhibit a decrease in compressive stress as crystallization proceeds while an increase in compressive stress followed by a decrease in stress is observed when crystallization is laser-induced. Raman spectroscopy has been used to characterize the crystallization ingrowth kinetics and is used in this work as a real time probe of both film temperature and localized stress which can be evaluated from shifts in lattice phonon frequencies measured in real time during laser irradiation. The laser not only induces the phase transformation but excites inelastic Raman scattering from which film stress and temperature can be estimated. A second approach for the determination of these parameters requires incorporation of a thin ruby film between the titania and silica substrate. Here, the wavelength shift of the laser-induced ruby fluorescence can be used to quantify interfacial stress; the fluorescence lifetime measurements are used to determine temperature. The advantages and limitations of these techniques for evaluating transient stress and temperature evolution in thin titania films subjected to CW laser irradiation will be discussed.

Citation Download Citation

Gregory J. Exarhos, Nancy J. Hess, and Susanne Wood "Transient stress evolution and crystallization in laser-irradiated amorphous titania sol-gel films", Proc. SPIE 1624, Laser-Induced Damage in Optical Materials: 1991, (29 July 1992); https://doi.org/10.1117/12.60094

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available