Neodymium(III) sulfate explained

Neodymium(III) sulfate is a salt of the rare-earth metal neodymium 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.^[1] This compound is used in glass for extremely powerful lasers.

Preparation

Neodymium sulfate is produced by dissolving neodymium(III) oxide in sulfuric acid:

It can also be prepared by the reaction of neodymium(III) perchlorate and sodium sulfate.

Properties

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.^[2]

Notes and References

1. Art. A. Migdisov . V. V. Reukov . A. E. Williams-Jones . A spectrophotometric study of neodymium(III) complexation in sulfate solutions at elevated temperatures . Geochimica et Cosmochimica Acta . 2005 . 70 . 4 . 983–992 . 10.1016/j.gca.2005.11.001 . en.
2. Wendlandt, W W . The thermal decomposition of yttrium and the rare earth metal sulphate hydrates . J. Inorg. & Nuclear Chem. . 1958 . 7 . 1–2 . 51–54 . en . 10.1016/0022-1902(58)80026-3.