Terbium sulfate fluorescing in a plastic bag
| IUPAC name
| Other names
|Appearance||White crystalline solid|
|Melting point||360 °C (680 °F; 633 K) (decomposes)|
|Solubility||Insoluble in hydrocarbons|
|Vapor pressure||~0 mmHg|
|Safety data sheet||Sigma-Aldrich|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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.
Terbium 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.
Terbium sulfate should be kept in closed plastic or glass bottles, away from moisture and acids.
Due to the rarity of terbium, it's best to recycle it.
- David R. Lide (Hrsg.): CRC Handbook of Chemistry and Physics. 90. Auflage. (Internet-Version: 2010), CRC Press/Taylor and Francis, Boca Raton, FL, Properties of the Elements and Inorganic Compounds, S. 4-94