Cerium(III) bromide
Encyclopedia
Cerium bromide is an inorganic compound
with the formula CeBr3. This white hygroscopic solid is of interest as a component of scintillation counter
s.
.Aqueous solutions of CeBr3 can be prepared from the reaction of Ce2(CO3)3·H2O with HBr. The product, CeBr3·H2O can be dehydrated by heating with NH4Br followed by sublimation of residual NH4Br. CeBr3 can be distilled at reduced pressure (~ 0.1 Pa) in a quartz ampoule at 875-880 °C.
Like the related salt CeCl3
, the bromide absorbs water on exposure to moist air. The compound melts congruently at 722 °C, and well ordered single crystals may be produced using standard crystal growth methods like Bridgman or Czochralski
.
CeBr3 adopts the hexagonal, UCl3-type crystal structure with P63/m Space group
.
Undoped single crystals of CeBr3 have shown promise as a γ-ray
scintillation detector
in nuclear non-proliferation testing, medical imaging, environmental remediation, and oil exploration.
Inorganic compound
Inorganic compounds have traditionally been considered to be of inanimate, non-biological origin. In contrast, organic compounds have an explicit biological origin. However, over the past century, the classification of inorganic vs organic compounds has become less important to scientists,...
with the formula CeBr3. This white hygroscopic solid is of interest as a component of scintillation counter
Scintillation counter
A scintillation counter measures ionizing radiation. The sensor, called a scintillator, consists of a transparent crystal, usually phosphor, plastic , or organic liquid that fluoresces when struck by ionizing radiation. A sensitive photomultiplier tube measures the light from the crystal...
s.
Preparation and basic properties
The compound has been known since at least 1899, when Muthman and Stützel reported its preparation from cerium sulfide and gaseous HBrHydrogen bromide
Hydrogen bromide is the diatomic molecule HBr. HBr is a gas at standard conditions. Hydrobromic acid forms upon dissolving HBr in water. Conversely, HBr can be liberated from hydrobromic acid solutions with the addition of a dehydration agent, but not by distillation. Hydrogen bromide and...
.Aqueous solutions of CeBr3 can be prepared from the reaction of Ce2(CO3)3·H2O with HBr. The product, CeBr3·H2O can be dehydrated by heating with NH4Br followed by sublimation of residual NH4Br. CeBr3 can be distilled at reduced pressure (~ 0.1 Pa) in a quartz ampoule at 875-880 °C.
Like the related salt CeCl3
Cerium(III) chloride
Cerium chloride , also known as cerous chloride or cerium trichloride, is a compound of cerium and chlorine. It is a white hygroscopic solid; It rapidly absorbs water on exposure to moist air to form a hydrate which appears to be of variable composition, though the heptahydrate CeCl3·7 H2O is known...
, the bromide absorbs water on exposure to moist air. The compound melts congruently at 722 °C, and well ordered single crystals may be produced using standard crystal growth methods like Bridgman or Czochralski
Czochralski process
The Czochralski process is a method of crystal growth used to obtain single crystals of semiconductors , metals , salts, and synthetic gemstones...
.
CeBr3 adopts the hexagonal, UCl3-type crystal structure with P63/m Space group
Space group
In mathematics and geometry, a space group is a symmetry group, usually for three dimensions, that divides space into discrete repeatable domains.In three dimensions, there are 219 unique types, or counted as 230 if chiral copies are considered distinct...
.
Applications
CeBr3-doped lanthanum bromide single crystals are known to exhibit superior scintillation properties for applications in the security, medical imaging, and geophysics detectors.Undoped single crystals of CeBr3 have shown promise as a γ-ray
scintillation detector
Scintillator
A scintillator is a special material, which exhibits scintillation—the property of luminescence when excited by ionizing radiation. Luminescent materials, when struck by an incoming particle, absorb its energy and scintillate, i.e., reemit the absorbed energy in the form of light...
in nuclear non-proliferation testing, medical imaging, environmental remediation, and oil exploration.