Thallium: Encyclopedia II - Thallium - Applications

Thallium - Applications

The odorless and tasteless thallium sulfate was widely used in the past as a rat poison and ant killer. In the United States and many other countries this use is no longer allowed due to safety concerns. Other uses:

• thallium sulfide's electrical conductivity changes with exposure to infrared light therefore making this compound useful in photocells.
• thallium bromide-iodide crystals have been used as infrared optical materials.
• thallium oxide has been used to manufacture glasses that have a high index of refraction.
• used in semiconductor materials for selenium rectifiers,
• in gamma radiation detection equipment,
• high-density liquid used for sink-float separation of minerals,
• used in the treatment of ringworm and other skin infections. However this use has been limited due to the narrow margin that exists between toxicity and therapeutic benefit.
• radioactive thallium-201 is used for diagnostic purposes in nuclear medicine, particularly in stress tests used for risk stratification in patients with coronary artery disease (CAD).
• combined with sulfur or selenium and arsenic, thallium has been used in the production of high-density glasses that have low melting points in the range of 125 and 150 °C. These glasses have room temperature properties that are similar to ordinary glasses and are durable, insoluble in water and have unique refractive indexes.
• thallium amalgam is used in thermometers for low temperature, because it freezes at -58 degree celsius (poor mercury freezes at -38 degree celsius)

In addition, research activity with thallium is ongoing to develop high-temperature superconducting materials for such applications as magnetic resonance imaging, storage of magnetic energy, magnetic propulsion, and electric power generation and transmission.

Adapted from the Wikipedia article "Applications", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki