Promethium(III) sulfide


Promethium sulfide is a binary inorganic compound with the chemical formula.

Synthesis

Promethium sulfide can be produced by treating metallic promethium with sulfur:
Once prepared, promethium sulfide can be purified by chemical vapor transport using iodine.
Promethium sulfide can also be prepared by treating the sulfate with hydrogen sulfide at elevated temperatures:

Physical properties

The compound forms garnet red crystals of the orthorhombic system, space group I3''d and exists in α'' and β forms.