The ternary Ho–V–Ga system at 750 °C, and new rare earth vanadium and chromium gallides

• Isothermal section of the Ho–V–Ga at 750 °C was investigated.
• Five new REV2Ga4 compounds with YbMo2Al4 type were studied.
• Six new RECr4Ga8 phases with ScFe6Ga6 type were discovered.

The ternary Ho–V–Ga phase diagram has been investigated at 750 °C by means of powder X–ray diffraction analysis and energy–dispersive X–ray spectroscopy. The studied system is characterized by the absence of detectable solubility for the binary compounds and by the existence of two new ternary phases, HoV2Ga4 (YbMo2Al4 structure type) and Ho4V1–xGa12 (0 ≤ x < 1, related to the AuCu3 structure type). Isostructural representatives REV2Ga4 have been found for RE = Tb, Dy and Tm and confirmed for RE = Er. Additionally, the formation of the new RECr4Ga8 phases (related to the ScFe6Ga6 structure type) with RE = Gd–Tm has been revealed. Structural peculiarities and interactions of the atoms in the HoV2Ga4 and HoCr4Ga8 compounds have been briefly discussed.

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