Phase equilibria in the system CeNiC at 800 in the range 0-33.3 at.% Ce and new isostructural compounds R2Ni5C3 (R = Pr, Nd)

 

Chem. Met. Alloys 9 (2016) 34-41

 

Mykola HEMBARA, Volodymyr LEVYTSKYY, Volodymyr BABIZHETSKYY, Bogdan KOTUR

 

The phase equilibria in the ternary system CeNiC at 800C 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 CeNi and CeC compounds at 800C 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