Erbium(III) selenide

Erbium(III) selenide is an inorganic compound with a chemical formula of Er2Se3.

Preparation
Erbium(III) selenide can be obtained by the reaction of erbium and selenium:


 * 2 Er + 3 Se -> Er2Se3

It can also be prepared by reacting erbium oxide and hydrogen selenide at high temperature.


 * Er2O3 + 3 H2Se -> Er2Se3 + 3 H2O

Properties
Erbium(III) selenide is an orthorhombic crystal with a Sc2S3 structure and a space group of Fddd. It reacts with magnesium selenide at 1000 °C to obtain MgEr2Se4.