Neodymium(III) sulfate is a salt of the rare-earth metalneodymium that has the formula Nd2(SO4)3. It forms multiple hydrates, the octa-, penta-, and the dihydrate, which the octahydrate is the most common. This compound has a retrograde solubility, unlike other compounds, its solubility decreases with increasing temperature.[3] This compound is used in glass for extremely powerful lasers.
Neodymium sulfate octahydrate decomposes at 40 °C to the pentahydrate, which in turn decomposes to the dihydrate at 145 °C. The dihydrate dehydrates to the anhydrous form at 290 °C.[4]
^Art. A. Migdisov; V. V. Reukov; A. E. Williams-Jones (2005). "A spectrophotometric study of neodymium(III) complexation in sulfate solutions at elevated temperatures". Geochimica et Cosmochimica Acta. 70 (4): 983–992. doi:10.1016/j.gca.2005.11.001.
^Wendlandt, W W (1958). "The thermal decomposition of yttrium and the rare earth metal sulphate hydrates". J. Inorg. & Nuclear Chem. 7 (1–2): 51–54. doi:10.1016/0022-1902(58)80026-3.