Refractive index database

nk database   |   n2 database   |   about




Optical constants of ThF4 (Thorium tetrafluoride)
Heitmann and Ritter 1976: n 0.26–0.76 µm

Wavelength: µm

Complex refractive index (n+ik)[ i ]

n   k   LogX   LogY   eV

Derived optical constants

Dispersion formula [ i ]



ThF4 film on quartz glass


W. Heitmann and E. Ritter. Production and properties of vacuum evaporated films of thorium fluoride, Appl. Opt. 7, 307-309 (1968)
(Digitization of graphical data and fitting with the Sellmeier dispersion formula:


[Expressions for n]   [CSV - comma separated]   [TXT - tab separated]   [Full database record]


Thorium tetrafluoride, ThF4

Thorium tetrafluoride (ThF4) is a white crystalline solid and is one of the principal halide compounds of thorium. Due to its high melting point and low refractive index, it has been investigated as a potential material for optical windows, especially in the infrared range. ThF4 has been found to possess favorable transmission properties in the mid and far-infrared spectrum, making it suitable for some infrared optics applications. Furthermore, as with many thorium compounds, it is radioactive because thorium is predominantly found as the isotope Th-232, which decays over time. Handling and use of ThF4 therefore require precautions to protect against radiation exposure. The compound also serves as an intermediate in the processing of thorium from its ores and can be a precursor to other thorium compounds in various chemical processes.

Other names

  • Thorium(IV) fluoride
  • Thorium fluoride

External links