Gadolinium(III) sulfate is an inorganic compound with the chemical formula . The octahydrate forms colorless monoclinic crystals.
Structure and properties The octahydrate forms monoclinic crystals where Gd is coordinated by 4 oxygen atoms of crystal water and 4 oxygens of sulfate giving rise to a distorted square antiprism.
It dehydrates in a two-step mechanism occurring between 130 and 306 °C, forming an amorphous solid. Recrystallization occurs between 380 and 411 °C, forming β-. A monotropic phase transition occurs at about 750 °C, forming α- (space group: C2/c, a = 9.097 Å, b = 14.345 Å, c = 6.234 Å, β = 97.75°). Upon further heating, the oxysulfate () forms at 900 °C, which decomposes into cubic gadolinium oxide at 1200 °C.
Preparation The octahydrate can be prepared by treating gadolinium oxide with sulfuric acid.
Applications Gadolinium sulfate was introduced into the Super-Kamiokande neutrino observatory in order to improve its neutron detection efficiency.
It is used in adiabatic demagnetization to achieve cryogenic temperatures.
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