Terbium sulfate is an ionic compound with the formula Tb2(SO4)3. It is notable for being extremely fluorescent, emitting bright green light under shortwave ultraviolet light. It is relatively insoluble in water, especially when precipitated with potassium sulfate, forming a double sulfate with the formula KTb(SO4)2.
Terbium sulfate is generally inert to reduction or oxidation. Heating to approximately 1500 degrees Celsius, however, produces terbium(III,IV) oxide. Its solubility in water decreases with heating, but it has a tendency to supersaturate, and a supersaturated solution of terbium sulfate may not crystallize for days.
PhysicalEditTerbium sulfate appears to crystallize in the hexagonal crystal system. It is a white solid that can be quite powdery when crushed. As a powder, it passes very easily through filter paper.
Terbium sulfate is extremely difficult to find at a reasonable price, but the materials needed for preparation, terbium metal and sulfuric acid, can be found quite easily.
Terbium sulfate can be made by adding terbium metal to sulfuric acid. Terbium sulfate, however, does not dissolve in water easily, so stirring the metal to remove the layers of terbium sulfate powder helps greatly.
- Make fluorescent crystals
Terbium sulfate does not appear to be particularly toxic.