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

Abstract 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, HoV 2 Ga 4 (YbMo 2 Al 4 structure type) and Ho 4 V 1– x Ga 12 (0 ≤  x 3 structure type). Isostructural representatives REV 2 Ga 4 have been found for RE = Tb, Dy and Tm and confirmed for RE = Er. Additionally, the formation of the new RECr 4 Ga 8 phases (related to the ScFe 6 Ga 6 structure type) with RE = Gd–Tm has been revealed. Structural peculiarities and interactions of the atoms in the HoV 2 Ga 4 and HoCr 4 Ga 8 compounds have been briefly discussed.