Abstract

Silicon tetrafluoride (SiF₄) and sulfur hexafluoride (SF₆) are widely used as sensitizing agents in photochemical experiments in the infrared region of the spectrum. These experiments include chemical vapor deposition, powder formation (for a review see Ref. 1), and kinetics. The energy of the Si-F bond is 610 kJ mol^-1, whereas that of the corresponding S-F bond is 300 kJ mol^-1. Therefore, SiF₄ is expected to be a more versatile sensitizing agent than SF₆, since the relatively high Si-F bond energy allows for greater radiative energy input and higher effective reaction temperatures. The high effective temperatures attained with the use of SiF₄ (or SF₆) necessitate the study of the absorptivities of these materials, since that quantity is known to be temperature dependent. Unfortunately, although some experimental results have been reported for SF₆, such data are not generally available for SiF₄. Moreover, in the case of laser-excited experiments, there is the potential for photochemical bleaching. Again, such data have been obtained for SF₆, but only a limited amount of information is available for SiF₄. In this study, we report on the absorptivity as a function of sample pressure (temperature) and as a function the continuous-wave (cw) laser power for conditions typically employed in sensitized infrared-driven chemical processes. It may be readily observed from the presented data that the absorptivity decreases with increasing laser power and that a limiting temperature is reached for increasing sample pressure at a constant laser power.

CO₂ laser coincidences with ν₃ of SiF₄ near 9.7 μm

Robin S. McDowell, Chris W. Patterson, Norris G. Nereson, F. R. Petersen, and J. S. Wells
Opt. Lett. 6(9) 422-424 (1981)

High-gain 87 cm⁻¹ Raman line of KYW and its impact on continuous-wave Raman laser operation

Soumya Sarang, Robert J. Williams, Oliver Lux, Ondrej Kitzler, Aaron McKay, Hadiya Jasbeer, and Richard P. Mildren
Opt. Express 24(19) 21463-21473 (2016)

High-power continuous-wave Cr⁴⁺:forsterite laser

Anatoliy Ivanov, Vladislav Shcheslavskiy, Vladislav Yakovlev, Boris Minkov, and Alexander Vasiliev
Appl. Opt. 40(33) 6034-6037 (2001)

Evidence of tumbling multiplets in saturation absorption spectra of SiF₄

William G. Harter, Howard P. Layer, and F. R. Petersen
Opt. Lett. 4(3) 90-92 (1979)

High-power stable continuous-wave single-longitudinal-mode Nd:YVO₄ laser at 1342 nm

Yayun Ma, Yuanji Li, Jinxia Feng, and Kuanshou Zhang
Opt. Express 26(2) 1538-1546 (2018)