| 词条 | Caesium iodide | |||||||||||||
| 释义 |
| Watchedfields = changed | verifiedrevid = 476994560 | Name = Caesium iodide | ImageFile1 =Kristall CsI(Ti).JPG | ImageCaption1 =CsI crystal | ImageFile2 =Kristall-CsI(Tl) mit Skala.jpg | ImageCaption2 =Scintillating CsI crystal | ImageFile3 = CsCl polyhedra.png | ImageCaption3 =Crystal structure | ImageSize3 = | ImageName = Caesium iodide | IUPACName = Caesium iodide | OtherNames = Cesium iodide |Section1={{Chembox Identifiers | InChI = 1/Cs.HI/h;1H/q+1;/p-1 | SMILES = [Cs+].[I-] | InChIKey = XQPRBTXUXXVTKB-REWHXWOFAA | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/Cs.HI/h;1H/q+1;/p-1 | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = XQPRBTXUXXVTKB-UHFFFAOYSA-M | CASNo = 7789-17-5 | CASNo_Ref = {{cascite|correct|CAS}}[1] | EC_number = 232-145-2 | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 23003 | PubChem = 24601 | RTECS = FL0350000 | UNII = U1P3GVC56L |Section2={{Chembox Properties | Formula = CsI | MolarMass = 259.809 g/mol[2] | Appearance = white crystalline solid | Density = 4.51 g/cm3[2] | Solubility = 848 g/L (25 °C)[2] | MeltingPtC = 632 | BoilingPtC = 1280 | MeltingPt_ref =[2] | BoilingPt_ref =[2] | RefractIndex = 1.9790 (0.3 µm) 1.7873 (0.59 µm) 1.7694 (0.75 µm) 1.7576 (1 µm) 1.7428 (5 µm) 1.7280 (20 µm)[3] | MagSus = -82.6·10−6 cm3/mol[4] |Section3={{Chembox Structure | CrystalStruct = CsCl, cP2 | SpaceGroup = Pm{{overline|3}}m, No. 221[5] | LattConst_a = 0.4503 nm | UnitCellFormulas = 1 | UnitCellVolume = 0.0913 nm3 | Coordination = Cubic (Cs+) Cubic (I−) |Section5={{Chembox Thermochemistry | DeltaHf = −346.6 kJ/mol[6] | Entropy = 123.1 J/mol·K[6] | DeltaGf = -340.6 kJ/mol[6] | HeatCapacity = 52.8 J/mol·K[6] }} |Section7={{Chembox Hazards | GHSSignalWord = Warning | GHSPictograms = {{GHS07}}{{GHS08}}{{GHS09}} | HPhrases = {{H-phrases|315|317|319|335}} | PPhrases = {{P-phrases|201|202|261|264|270|271|272|273|280|281|301+312|302+352|304+340|305+351+338|308+313|312|321|330|332+313|333+313|337+313|362|363|391|403+233|405|501}} | ExternalSDS = | FlashPt = Non-flammable | LD50 = 2386 mg/kg (oral, rat)[1] |Section8={{Chembox Related | OtherAnions = Caesium fluoride Caesium chloride Caesium bromide Caesium astatide | OtherCations = Lithium iodide Sodium iodide Potassium iodide Rubidium iodide Francium iodide }}Caesium iodide or cesium iodide (chemical formula CsI) is the ionic compound of caesium and iodine. It is often used as the input phosphor of an X-ray image intensifier tube found in fluoroscopy equipment. Caesium iodide photocathodes are highly efficient at extreme ultraviolet wavelengths.[7] Synthesis and structureBulk caesium iodide crystals have the cubic CsCl crystal structure, but the structure type of nanometer-thin CsI films depends on the substrate material – it is CsCl for mica and NaCl for LiF, NaBr and NaCl substrates.[9] Caesium iodide atomic chains can be grown inside double-wall carbon nanotubes. In such chains I atoms appear brighter than Cs atoms in electron micrographs despite having a smaller mass. This difference was explained by the charge difference between Cs atoms (positive), inner nanotube walls (negative) and I atoms (negative). As a result, Cs atoms are attracted to the walls and vibrate more strongly than I atoms, which are pushed toward the nanotube axis.[8] Properties
ApplicationsAn important application of caesium iodide crystals, which are scintillators, is electromagnetic calorimetry in experimental particle physics. Pure CsI is a fast and dense scintillating material with relatively low light yield that increases significantly with cooling.[11] It shows two main emission components: one in the near ultraviolet region at the wavelength of 310 nm and one at 460 nm. The drawbacks of CsI are a high temperature gradient and a slight hygroscopicity. Caesium iodide is used as a beamsplitter in Fourier transform infrared (FTIR) spectrometers. It has a wider transmission range than the more common potassium bromide beamsplitters, extending its working range into the far infrared. However, optical-quality CsI crystals are very soft and hard to cleave or polish. They should also be coated (typically with germanium) and stored in a desiccator, to minimize interaction with atmospheric water vapors.[12] In addition to image intensifier input phosphors, caesium iodide is often also used in medicine as the scintillating material in flat panel x-ray detectors.[13] References{{Commons category|Caesium iodide}}1. ^1 Cesium iodide. U.S. National Library of Medicine 2. ^1 2 3 4 Haynes, p. 4.57 3. ^Haynes, p. 10.240 4. ^Haynes, p. 4.132 5. ^{{cite journal|doi=10.1103/PhysRevB.29.1112|title=Equation of state and high-pressure phase transition of CsI|journal=Physical Review B|volume=29|issue=2|pages=1112|year=1984|last1=Huang|first1=Tzuen-Luh|last2=Ruoff|first2=Arthur L.|bibcode=1984PhRvB..29.1112H}} 6. ^1 2 3 Haynes, p. 5.10 7. ^{{cite journal|doi=10.1364/AO.25.002440|pmid=18231513|title=Quantum efficiency of cesium iodide photocathodes at soft x-ray and extreme ultraviolet wavelengths|journal=Applied Optics|volume=25|issue=14|pages=2440|year=1986|last1=Kowalski|first1=M. P.|last2=Fritz|first2=G. G.|last3=Cruddace|first3=R. G.|last4=Unzicker|first4=A. E.|last5=Swanson|first5=N.|bibcode=1986ApOpt..25.2440K}} 8. ^1 {{cite journal|doi=10.1038/nmat4069|pmid=25218060|title=Atomic structure and dynamic behaviour of truly one-dimensional ionic chains inside carbon nanotubes|journal=Nature Materials|volume=13|issue=11|pages=1050|year=2014|last1=Senga|first1=Ryosuke|last2=Komsa|first2=Hannu-Pekka|last3=Liu|first3=Zheng|last4=Hirose-Takai|first4=Kaori|last5=Krasheninnikov|first5=Arkady V.|last6=Suenaga|first6=Kazu|bibcode=2014NatMa..13.1050S}} 9. ^{{cite journal|doi=10.1107/S0365110X51001641|title=Polymorphism of cesium and thallium halides|journal=Acta Crystallographica|volume=4|issue=6|pages=487|year=1951|last1=Schulz|first1=L. G.}} 10. ^Haynes, p. 5.191 11. ^{{cite journal|title=Luminescence and scintillation properties of CsI: A potential cryogenic scintillator|journal=Physica Status Solidi B|volume=252|issue=4|pages=804–810|year=2015|last1=Mikhailik|first1=V.|last2=Kapustyanyk|first2=V.|last3=Tsybulskyi|first3=V.|last4=Rudyk|first4=V.|last5=Kraus|first5=H.|doi=10.1002/pssb.201451464|arxiv=1411.6246|bibcode=2015PSSBR.252..804M}} 12. ^{{cite book|author=Sun, Da-Wen |title=Infrared Spectroscopy for Food Quality Analysis and Control|url=https://books.google.com/books?id=bOWUDeiYshsC&pg=PA158|date=2009|publisher=Academic Press|isbn=978-0-08-092087-0|pages=158–}} 13. ^{{cite book|last1=Lança|first1=Luís|last2=Silva|first2=Augusto|title=Digital Imaging Systems for Plain Radiography|date=2012|publisher=Springer|isbn=978-1-4614-5066-5|url=https://www.springer.com/cda/content/document/cda_downloaddocument/9781461450665-c1.pdf?SGWID=0-0-45-1368105-p174548440|chapter=Digital Radiography Detectors: A Technical Overview|doi=10.1007/978-1-4614-5067-2_2}} Cited sources
4 : Caesium compounds|Iodides|Alkali metal iodides|Metal halides |
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