The liquidus of the system Cu<sub>2</sub>S - Nd<sub>2</sub>S<sub>3</sub> - EuS
The position of the fields of the initial crystallization of the stages in the system Cu2S - Nd2S3 - EuS: γ-Cu2S, β-Cu2S, EuS, EuNdCuS3, γ-NdCuS2(EuNd2S4), NdCuS2 is determined on the basis of the phase diagrams forming the triple system Cu2S - Nd2S3 - EuS and on the basis of the phase diagrams of the sections Cu2S - EuNd-CuS3. The succession of changing of the binary eutectics in the interior part of the triangle is established. The isotherms of the surface of the liquidus are constructed.