KI

Potassium iodide (KI) is an ionic ceramic compound—a halide salt with a face-centered cubic crystal structure—valued for its optical transparency across the visible and infrared spectrum. It is widely used in scintillation detectors for radiation monitoring and medical imaging, in optics for infrared windows and lenses, and historically in photographic emulsions and pharmaceutical applications. Engineers select KI for its high refractive index, radiation detection efficiency, and ability to transmit mid-infrared wavelengths where many polymers absorb; however, its hygroscopicity and relative brittleness limit applications to dry, controlled environments.