Materials which are resistant to halogen fluoride solutions and transparent in the far infrared are limited. Of those we have tried, only diamond appears to be at all satisfactory. This note describes a cell in which diamond is used as the window material. With this cell, it is now possible to obtain ir spectra in the 200–900 cm−1 spectral region.
Herbert H. Hyman, Terry Surles, Lloyd A. Quarterman, and Alexander I. Popov, "A Diamond-Window Infrared Short Path Length Cell for Corrosive Liquids," Appl. Spectrosc. 24, 464-465 (1970)