The YNiCu ternary system at 600C

 

Chem. Met. Alloys 9 (2016) 1-10

 

Oksana MYAKUSH, Volodymyr BABIZHETSKYY, Volodymyr LEVYTSKYY, Bogdan KOTUR

 

The isothermal section of the YNiCu phase diagram at 600C has been investigated by means of X-ray diffraction and microstructure analyses. The homogeneity ranges of the solid solutions YNi5‑Cu (0 ≤  ≤ 4.6) (structure type CaCu5, space group P6/mmm a 0.48861(2)0.50080(4), = 0.39592(2)0.40740(4) nm), Y2Ni17‑Cu (0 ≤  ≤ 7.8) (structure type Th2Ni17, space group P63/mmc, a 0.8314(1)0.8387(1), c = 0.8042(1)0.8117(1) nm), YCu67Nix (0 ≤  ≤ 0.28) (structure type TbCu7, space group P6/mmm, a = 0.49470(4)0.49540(4), c = 0.4133(4)0.4227(4) nm) were refined. It was found that the maximal solubility of the third component does not exceed 3.8 at.% in Y2Cu7 and less than 1 at.% in Y2Ni7, YCu, and YCu4. The crystal structure of a single crystal of composition YNi4Cu (YNi5‑Cu solid solution) was investigated by X-ray diffraction: = 0.4899(2), = 0.3979(3) nm, R1 = 0.028 for 57 independent reflections with Io ≥ 2σ(Io), wR2 = 0.058. A new ternary compound, YNi2.850.75Cu1.153.25, of unknown structure with an extended homogeneity range, was found.

 

 

Phase equilibria in the YNiCu system at 600C

 

Keywords

Intermetallics / Rare-earth metal system / Phase diagram / X-ray diffraction