Investigation of the Nd^sub 2^O^sub 3^–Lu^sub 2^O^sub 3^–Sc^sub 2^O^sub 3^ phase diagram for the preparation of perovskite-type mixed crystals NdLu^sub 1−x^Sc^sub x^O^sub 3

Based on differential thermal analysis (DTA) and X-ray powder diffraction (XRD), a description of the Nd2O3–Lu2O3–Sc2O3 system was obtained by thermodynamic assessment. Four fields of primary crystallization could be identified; from melt compositions close to the Lu2O3–Sc2O3 edge, the rare-earth oxide C-phase crystallizes first which is stable down to room temperature. From Nd2O3 rich melts, the X-phase forms which is stable only at high temperatures. An additional field, where the alternative high-temperature phase H solidifies as primary product touches the Nd2O3–Lu2O3 edge of the concentration triangle. From melts close to the composition NdScO3, the P-phase (perovskite) can be crystallized and mixed crystals with second endmember NdLuO3 have been grown from the melt. Crystals of this mixed perovskite were grown by the micro-pulling-down and Czochralski methods.