Incoming links: Uranium isotope
Uranium-235 neutron cross section as a function of neutron energy
. Source. Neutron cross section for various uranium isotopes
. Source. 
This is an important man-made uranium compound as it is used in uranium enrichment.
The main reason for this is that fluorine only has one stable isotope, which allows you to pick up weight differences in uranium isotopes in isolation.
Ball model of uranium hexafluoride
. Source. Hex sublimates at around 56.5 °C at so it can be converted to a gas relatively easily. It is then in its gas form that it is used for uranium enrichment
