Products Description of Cesium Iodide CAS#7789-17-5
Cesium iodide (CsI) and other inorganic halides like CsI(Tl) are go-to materials for scintillation in high-energy particle detection and radiation detectors. Vacuum-deposited CsI(Tl) thin films were actually some of the first scintillators ever used in X-ray imaging with photoelectric conversion systems.
In modern digital X-ray imaging, CsI(Tl) films are widely used because they're great at converting X-rays into light, offer high spatial resolution, and work well with silicon-based readout systems. Together, these properties deliver clear, precise images.
Cesium iodide Chemical Properties
| Melting point | 626 °C (lit.) |
| Boiling point | 1280 °C |
| density | 4.51 g/mL at 25 °C (lit.) |
| refractive index | 1.7876 |
| Fp | 1280°C |
| storage temp. | Keep in dark place,Inert atmosphere,Room temperature |
| solubility | soluble in ethanol, methanol, acetone |
| form | beads |
| Specific Gravity | 4.51 |
| color | White |
| PH | pH(50g/l, 25℃) : 5.0～9.0 |
| Water Solubility | 74 g/100 mL (20 ºC) |
| Sensitive | Hygroscopic |
| Merck | 142014 |
| Exposure limits | ACGIH: TWA 0.01 ppm |
| Dielectric constant | 5.6（Ambient） |
| Stability: | Stable. Deliquescent. |
| CAS DataBase Reference | 7789-17-5(CAS DataBase Reference) |
| NIST Chemistry Reference | Cesium iodide(7789-17-5) |
| EPA Substance Registry System | Cesium iodide (CsI) (7789-17-5) |
| Hazard Codes | Xn,Xi |
| Risk Statements | 36/37/38-42/43-43 |
| Safety Statements | 22-36/37-45 |
| RIDADR | UN 3077 9 / PGIII |
| WGK Germany | 2 |
| RTECS | FL0350000 |
| F | 8 |
| TSCA | Yes |
| HS Code | 28276000 |
| Toxicity | LD50 i.p. in rats: 1.4 g/kg (Cochran) |
Product Application of Cesium Iodide CAS#7789-17-5
Cesium iodide crystals are commonly used as scintillation materials in electromagnetic calorimeters for particle physics experiments. They're also found in FT-IR spectrometers, where they serve as optical components thanks to their great infrared transmission.
Compared to the more common potassium bromide spectroscopes, cesium iodide can transmit light over a broader range, reaching into the far-infrared. But there's a catch—the crystals are relatively soft and don't have cleavage planes, so getting a smooth, highly polished surface is tough.
You also need to store cesium iodide optical crystals in a dry place so they don't react with moisture. Applying a germanium coating to the surface can really help cut down on humidity problems when you're handling or replacing the spectroscope.
