METHOD FOR PRODUCING HALIDE

WIPO Patent Application WO/2021/199643

A1

The production method of the present disclosure includes a firing step for firing a mixture that includes (NH4)aYα3+a, (NH4)bSmβ3+b, Liγ, and Caδ2 in an inert gas atmosphere, where α, β, γ, and δ each independently are at least one selected from the group consisting of F, Cl, Br, and I, and the following three numerical formulas: 0≤a≤3, 0≤b≤3, and 0