Lanthanum oxysulfide

Lanthanum oxysulfide is an inorganic compound, a salt of lanthanum and hydrogen sulfide acid, with the formula.

Synthesis

 * Calcination of lanthanum(III) sulfate in oxygen current at 750 °C:
 * La2(SO4)3 + O2 -> La2O3*SO3 + 2SO3


 * The resulting product is reduced with hydrogen when heated:
 * La2O3*SO3 + 4H2 -> La2O2S + 4H2O

Physical properties
The compound forms yellowish-white hexagonal crystals.

Uses
The compound is used as a laser host material.