يوديد السيزيوم

Caesium iodide
Caesium iodide
CsI crystal
Kristall-CsI(Tl) mit Skala.jpg
Scintillating CsI crystal
CsCl polyhedra.png
Crystal structure
Caesium-iodide-3D-ionic.png
الأسماء
اسم أيوپاك
Caesium iodide
أسماء أخرى
Cesium iodide
المُعرِّفات
رقم CAS
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.223 Edit this at Wikidata
رقم EC
  • 232-145-2
رقم RTECS
  • FL0350000
UNII
الخصائص
الصيغة الجزيئية CsI
كتلة مولية 259.809 g/mol[2]
المظهر white crystalline solid
الكثافة 4.51 g/cm3[2]
نقطة الانصهار
نقطة الغليان
قابلية الذوبان في الماء 848 g/L (25 °C)[2]
القابلية المغناطيسية -82.6·10−6 cm3/mol[4]
معامل الانكسار (nD) 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]
البنية
البنية البلورية CsCl, cP2
الزمرة الفراغية Pm3m, No. 221[5]
ثابت العقد a = 0.4503 nm
هندسة
إحداثية
Cubic (Cs+)
Cubic (I)
الكيمياء الحرارية
الإنتالپية المعيارية
للتشكل
ΔfHo298
−346.6 kJ/mol[6]
Standard molar
entropy
So298
123.1 J/mol·K[6]
سعة الحرارة النوعية، C 52.8 J/mol·K[6]
المخاطر
ن.م.ع. مخطط تصويري The exclamation-mark pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)رمز الخطر على الصحة في النظام المنسق عالمياً لتصنيف وعنونة الكيماويات (GHS)رمز البيئة في النظام المنسق عالمياً لتصنيف وعنونة الكيماويات (GHS)
ن.م.ع. كلمة الاشارة Warning
H315, H317, H319, H335
P201, P202, P261, P264, P270, P271, P272, P273, P280, P281, P301+P312, P302+P352, P304+P340, P305+P351+P338, P308+P313, P312, P321, P330, P332+P313, P333+P313, P337+P313, P362, P363, P391, P403+P233, P405, P501
نقطة الوميض Non-flammable
الجرعة أو التركيز القاتل (LD, LC):
2386 mg/kg (oral, rat)[1]
مركبات ذا علاقة
Caesium fluoride
Caesium chloride
Caesium bromide
Caesium astatide
Lithium iodide
Sodium iodide
Potassium iodide
Rubidium iodide
Francium iodide
ما لم يُذكر غير ذلك، البيانات المعطاة للمواد في حالاتهم العيارية (عند 25 °س [77 °ف]، 100 kPa).
YesY verify (what is YesYX mark.svgN ?)
مراجع الجدول

يوديد السيزيوم Caesium iodide أو cesium iodide (الصيغة الكيميائية 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]

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التخليق والبنية

Monatomic caesium halide wires grown inside double-wall carbon nanotubes.[8]

Bulk 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]


الخصائص

قابلية ذوبان Csl في الماء[10]
Т (°C) 0 10 20 25 30 40 50 60 70 80 90 100
S (wt%) 30.9 37.2 43.2 45.9 48.6 53.3 57.3 60.7 63.6 65.9 67.7 69.2

التطبيقات

An 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, 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]

المراجع

  1. ^ أ ب Cesium iodide. U.S. National Library of Medicine
  2. ^ أ ب ت خطأ استشهاد: وسم <ref> غير صحيح؛ لا نص تم توفيره للمراجع المسماة b92
  3. ^ Haynes, p. 10.240
  4. ^ Haynes, p. 4.132
  5. ^ Huang, Tzuen-Luh; Ruoff, Arthur L. (1984). "Equation of state and high-pressure phase transition of CsI". Physical Review B. 29 (2): 1112. Bibcode:1984PhRvB..29.1112H. doi:10.1103/PhysRevB.29.1112.
  6. ^ أ ب ت Haynes, p. 5.10
  7. ^ Kowalski, M. P.; Fritz, G. G.; Cruddace, R. G.; Unzicker, A. E.; Swanson, N. (1986). "Quantum efficiency of cesium iodide photocathodes at soft x-ray and extreme ultraviolet wavelengths". Applied Optics. 25 (14): 2440. Bibcode:1986ApOpt..25.2440K. doi:10.1364/AO.25.002440. PMID 18231513.
  8. ^ أ ب Senga, Ryosuke; Komsa, Hannu-Pekka; Liu, Zheng; Hirose-Takai, Kaori; Krasheninnikov, Arkady V.; Suenaga, Kazu (2014). "Atomic structure and dynamic behaviour of truly one-dimensional ionic chains inside carbon nanotubes". Nature Materials. 13 (11): 1050–4. Bibcode:2014NatMa..13.1050S. doi:10.1038/nmat4069. PMID 25218060.
  9. ^ Schulz, L. G. (1951). "Polymorphism of cesium and thallium halides". Acta Crystallographica. 4 (6): 487–489. Bibcode:1951AcCry...4..487S. doi:10.1107/S0365110X51001641.
  10. ^ Haynes, p. 5.191
  11. ^ Mikhailik, V.; Kapustyanyk, V.; Tsybulskyi, V.; Rudyk, V.; Kraus, H. (2015). "Luminescence and scintillation properties of CsI: A potential cryogenic scintillator". Physica Status Solidi B. 252 (4): 804–810. arXiv:1411.6246. Bibcode:2015PSSBR.252..804M. doi:10.1002/pssb.201451464. S2CID 118668972.
  12. ^ Sun, Da-Wen (2009). Infrared Spectroscopy for Food Quality Analysis and Control. Academic Press. pp. 158–. ISBN 978-0-08-092087-0.
  13. ^ Lança, Luís; Silva, Augusto (2012). "Digital Radiography Detectors: A Technical Overview" (PDF). Digital Imaging Systems for Plain Radiography. Springer. doi:10.1007/978-1-4614-5067-2_2. hdl:10400.21/1932. ISBN 978-1-4614-5066-5. Archived from the original (PDF) on 2019-01-28. Retrieved 2017-08-28.

المصادر المستخدمة

HI He
LiI BeI2 BI3 CI4 NI3 I2O4, I2O5, I4O9 IF, IF3, IF5, IF7 Ne
NaI MgI2 AlI3 SiI4 PI3, P2I4 S ICl, ICl3 Ar
KI CaI2 Sc TiI4 VI3 Cr MnI2 Fe CoI2 NiI2 CuI ZnI2 Ga2I6 GeI2, GeI4 AsI3 Se IBr Kr
RbI SrI2 Y ZrI4 Nb Mo Tc Ru Rh Pd AgI CdI2 InI3 SnI4, SnI2 SbI3 TeI4 I Xe
CsI BaI2   Hf Ta W Re Os Ir Pt AuI Hg2I2, HgI2 TlI PbI2 Bi Po At Rn
Fr Ra   Rf Db Sg Bh Hs Mt Ds Rg Uub Uut Uuq Uup Uuh Uus Uuo
La Ce Pr Nd Pm SmI2 Eu Gd TbI3 Dy Ho Er Tm Yb Lu
Ac ThI4 Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr