A method is described for obtaining infrared spectra of an organic monolayer film on muscovite mica. This task is normally difficult because mica is not metallic, and it has biaxial optical properties and produces large interference fringes when analyzed in transmission or reflection because of reflections off the front and back of a sheet. The method involves the transmission of parallel-polarized light, incident at the Brewster's angle, through a mica sheet that is oriented along one of its principal optical directions.
George Carson and Steve Granick, "Infrared Spectra of Organic Monolayers on Mica," Appl. Spectrosc. 43, 473-476 (1989)