New compounds with Sc2Re3Si4-type structure in the systems R{Zr,Hf}Ge

 

Chem. Met. Alloys 8 (2015) 98-105

 

Maryna BOYKO, Nataliya MUTS, Yaroslav TOKAYCHUK, Roman GLADYSHEVSKII

 

Fifteen Sc2Re3Si4-type (Pearson symbol tP36, space group P41212) compounds, Y2{Zr,Hf}3Ge4, Gd2{Zr,Hf}3Ge4, Tb2{Zr,Hf}3Ge4, Dy2{Zr,Hf}3Ge4, Ho2Hf3Ge4, Er2{Zr,Hf}3Ge4, Tm2{Zr,Hf}3Ge4, and Lu2{Zr,Hf}3Ge4, were synthesized and characterized by means of X-ray diffraction and energy-dispersive analyses. The crystal structures of two alloys in the Tm-Zr-Ge and Ho-Hf-Ge systems (Tm0.88(4)Zr4.12(4)Ge4, a = 7.3457(5), c = 13.388(1) Å; Ho1.38(8)Hf3.62(8)Ge4, a = 7.3139(6), c = 13.3550(13) Å) were refined by the Rietveld method on X-ray powder diffraction data. In both structures one of the atom sites was found to be occupied by a statistical mixture of rare-earth metal and Zr (Hf) atoms.

 

Projection of the unit cell of the structure of Tm0.88(4)Zr4.12(4)Ge4 onto the bc plane and coordination polyhedra of the atoms

 

Keywords

Rare-earth metals / Zirconium / Hafnium / Germanium / X-ray powder diffraction / Crystal structure