Lutetium phosphide

Lutetium phosphide is an inorganic compound of lutetium and phosphorus with the chemical formula. The compound forms dark crystals, does not dissolve in water.

Synthesis
Heating powdered lutetium and red phosphorus in an inert atmosphere or vacuum:

It can also be formed in the reaction of lutetium and phosphine.

Physical properties
Lutetium phosphide forms dark cubic crystals, space group Fm$\overline{3}$m, cell parameters a = 0.5533 nm, Z = 4.

Stable in air, does not dissolve in water and reacts actively with nitric acid.

Uses
The compound is a semiconductor used in high power, high-frequency applications, and in laser diodes.

Also used in gamma radiation detectors due to its ability to absorb radiation.