Contribution to the investigation of the SmCuSn ternary system

 

Chem. Met. Alloys 9 (2016) 72-77

 

L. ROMAKA, V.V. ROMAKA, A. HORYN, Yu. STADNYK

 

The isothermal section of the phase diagram of the SmCuSn ternary system was constructed at 870 K in the whole concentration range based on X-ray diffraction and EPM analysis. The interaction between the elements results in the formation of five ternary compounds at this temperature: SmCuSn (NdPtSb-type), Sm3Cu4Sn4 (Gd3Cu4Ge4-type), SmCu5Sn (CeCu5Au-type), Sm1.9Cu9.2Sn2.8 (related to CeNi5Sn-type), and SmCu2Sn2 (CaBe2Ge2-type). DSC analyses showed a limited stability range for the Sm2Cu4Sn5 compound (up to 811 K), as well as for the isotypic R2Cu4-xSn5+x compounds with Pr (496-783 K) and Nd (671-791 K). Rietveld refinement of the crystal structure of SmCu5Sn confirmed CeCu5Au-type atom ordering (space group Pnma, a = 0.8267(1), b = 0.50087(6), c = 1.0601(1) nm).

 

 

Isothermal section of the SmCuSn system at 870 K.

 

Keywords

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