cesium iodide

chemical compound

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June 24, 2026

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Cesium iodide (CsI) is an ionic compound formed between the alkali metal cesium and the halogen iodine. Cesium (Cs) is a highly reactive, soft, silvery metal with a golden cast that melts just above room temperature. Iodine (I) is a nonmetallic element, appearing as a dark, lustrous solid that sublimes into a violet vapor.12

When combined, cesium iodide is used in applications such as scintillation counters and neutron detectors. Cesium itself is notable for its use in atomic clocks, which provide the world's time standard, and for its photoelectric properties, making it useful in photoelectric cells. Iodine is essential for human health, being a component of the hormone thyroxine produced by the thyroid gland.21

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spectroscopy
Infrared instrumentation
fluoride (CaF₂), zinc selenide (ZnSe), cesium iodide (CsI), or potassium bromide (KBr), coated with silicon or germanium are employed. Below 200 cm⁻¹ Mylar films of varying thickness are used to cover narrow portions of the region. Thermal detection of infrared radiation is based on the conversion of a temperature change,…
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fluoride (CaF₂), zinc selenide (ZnSe), cesium iodide (CsI), or potassium bromide (KBr), coated with silicon or germanium are employed. Below 200 cm⁻¹ Mylar films of varying thickness are used to cover narrow portions of the region. Thermal detection of infrared radiation is based on the conversion of a temperature change,…
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radiation measurement
Inorganic scintillators
Thallium-activated cesium iodide [CsI(Tl)] also produces excellent light yield but has two relatively long decay components with decay times of 0.68 and 3.3 microseconds. Its emission spectrum is shifted toward the longer-wavelength end of the visible spectrum and is a better match to the spectral response…
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Thallium-activated cesium iodide [CsI(Tl)] also produces excellent light yield but has two relatively long decay components with decay times of 0.68 and 3.3 microseconds. Its emission spectrum is shifted toward the longer-wavelength end of the visible spectrum and is a better match to the spectral response…
Read More