Terbium Uses

In a small quarry near Yetterby in Sweden, scientist Carl Gustaf Mosander discovered terbium during the great element rush. He separated three materials from the mineral ore gadolite. These three materials were named after his town Yetterby; yttria, erbia and terbia. The 'a' refers to the occurrence of the minerals in earth and those in combination with oxygen in chemistry. From these substances, Mosander further discovered two new elements, erbium and terbium. The first person to prepare a pure form was French chemist Jean Charles Galssard de Marignac.

Classification
The classification places it in the group of rare earth elements. It was placed in the rare group elements by early researchers not because it was rare to find from the belly of the earth, but because there were hardly any uses at that time. It is placed in the lanthanide group in the periodic table and the symbol is Tb. It has the atomic number 65 and its atomic mass is calculated at 158.9254.

Physical & Chemical Properties
IT has silver gray luster, like many metals. It is so soft that is can be cut into two with a knife. It is ductile and malleable, that is, it can be hammered into thin sheets or made into wires. Its melting point is 1,356° C or 2,473° F. The boiling point of the element is 2,800° C or 5,000° F.

It is not very active, like its brothers and sisters of the rare earth elements. It does not react with oxygen in the air easily and reacts slowly with water. It can dissolve readily in acids.

Compounds
Terbium combines with different elements at high temperatures like nitrogen, carbon, sulfur, phosphorous, boron, selenium, silicon and arsenic. In the compound state, it forms binary compounds with oxidation state +3 and +2. It can form compounds like TbH₂, TbH₃, TbB₂, Tb₂S₃, TbSe, TbTe and TbN and also sesquichloride Tb₂Cl₃.

Terbium isotopes that occur naturally is composed of 1 stable isotope, ¹⁵⁹Tb. It has been found that of the 33 radioisotopes ¹⁵⁸Tb is the most stable with a half life of 180 years. Similarly, ¹⁵⁷Tb has a half life of 71 years and ¹⁶⁰Tb has a half life of 72.3 days. Majority of the isotopes have half life less than 24 seconds and a few have half lives of 6.907 days.

What is it Used for?
The most common uses include as a laser material that emits coherent light at 5460Â. It is also used as a dopant for calcium fluoride, calcium tungstate and strontium molybdate that are used in solid state devices. It is also used as a probe in biochemistry as it resembles calcium in behavior. It gives out fluorescence that helps in tracking the element in biochemical experiments.

What is it Used in?
It is used in X-ray machines as well as a green phosphor activator in color television tubes. It is also used along with the element zirconium and works as a crystal stabilizer in fuel cells that are supposed to work at high temperatures. Terbium green phosphor is used in combination with divalent europium blue phosphors and trivalent europium red phosphors. This helps in creation of 'trichromatic' lighting technology that has a higher light output compared to incandescent lighting. It is also used in alloys, electronic devices and magnetomechanical devices.

The compounds have low to moderate toxicity in a biological cell. However, there is no known terbium use biologically. This was all about what it is used for.