Phase equilibria
in the system Ce–Ni–C at 800°Ñ in the range 0-33.3
at.% Ce and new isostructural
compounds R2Ni5C3
(R = Pr, Nd)
Chem.
Met. Alloys 9 (2016)
34-41
https://doi.org/10.30970/cma9.0319
Mykola HEMBARA, Volodymyr LEVYTSKYY,
Volodymyr BABIZHETSKYY, Bogdan KOTUR
The phase equilibria
in the ternary system Ce–Ni–C at 800°C in the range 0-33.3 at.% Ce were investigated by means of X-ray diffraction and
energy-dispersive spectroscopy. Three ternary, CeNiC2, Ce2Ni5C3,
and Ce2Ni22C2.75, and five binary Ce–Ni and Ce–C compounds at 800°C
were confirmed. Two new isostructural ternary
compounds (structure type La2Ni5C3,
space group P4/mbm): Pr2Ni5C3 (a = 8.2888(1) Å, c = 3.95343(8) Å) and Nd2Ni5C3 (a = 8.2810(2) Å, c = 3.9292(1) Å), were synthesized and their
crystal structures were refined. The compounds continue
the isostructural series of R2Ni5C3 ternary carbides with La2Ni5C3-type
structure.
Unit cell content and coordination polyhedra of the atoms in the crystal structure of the R2Ni5C3
ternary compounds (R = Ce, Pr, Nd) with La2Ni5C3-type
structure.
Keywords
Carbides
/ Phase equilibria / Crystal structure / Isostructural compounds