Thallium Bromide (TlBr) Semiconductors

Topics Covered

Chemical Properties
Electrical Properties
Thermal, Mechanical and Optical Properties
Safety Information


Thallium bromide is a chemical compound whose crystalline structure is of cubic CsCl type at room temperature. However, the structure transforms into orthorhombic thallium iodide type upon cooling. It exhibits semiconductor properties in an ultra-pure state. Thallium is highly toxic and can be easily absorbed through the skin.


Thallium bromide finds applications in the following:

  • X-ray and gamma-ray detectors
  • Photocells
  • Infrared optical materials.

Chemical Properties

The chemical properties of thallium bromide are provided in the table below:

Chemical Properties
Chemical Formula TlBr
Molecular Weight 284.287
CAS No. 7789-40-4
Group Thallium – 13
Bromine - 17
Crystal Structure Cubic

Electrical Properties

The electrical properties of thallium bromide are provided in the table below:

Electrical Properties
Magnetic Susceptibility -0.0000639
Dielectric Constant 30.3

Thermal, Mechanical and Optical Properties

The thermal, mechanical and optical properties of thallium bromide are provided in the tables below:

Thermal Properties
Heat of Fusion 57.7 J/g
Thermal Expansion Coefficient 51x10-6/°C
Specific Heat Capacity 188 J/kgK
Thermal Conductivity 0.586 W/mK
Mechanical Properties
Density 7.50 g/cm3
Melting Point 460°C
Boiling Point 819°C
Young’s Modulus 29.5 GPa
Shear Modulus 7.58 GPa
Bulk Modulus 22.47 GPa
Poisson Ratio 0.281
Knoop Hardness 11.9
Optical Properties
Refractive Index (@ 10 µm) 2.338
Refractive Loss (@ 10 µm) 27.70%

Safety Information

Safety Information
GHS Hazard Statements H300 - Fatal if swallowed
H330 - Fatal if inhaled
H373 - May cause damage to organs through prolonged or repeated exposure
H411 - Toxic to aquatic life with long lasting effects.
Safety Precautions P260 - Do not breathe dust/fume/gas/mist/vapors/spray
P264 - Wash your hands thoroughly after handling
P273 - Avoid release to the environment
P284 - Wear respiratory protection
P301+310 - If swallowed, immediately call a poison center or doctor/physician
P310 - Immediately call a poison center or doctor/physician.


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