Crystal structure of the quaternary phase Pr(Ni,Al,Ge)_2-x at the composition Pr(Ni_0.23Al_0.03Ge_0.74)_1.85

Chem. Met. Alloys 5 (2012) 166-172

https://doi.org/10.30970/cma5.0226

Nataliya MUTS, Oleg SHCHERBAN, Roman GLADYSHEVSKII

The crystal structure of Pr(Ni_0.23Al_0.03Ge_0.74)_1.85 (composition from EDX analysis) has been refined on powder and single-crystal X-ray diffraction data. The solid solution Pr(Ni,Al,Ge)_2-x, which extends from ternary Pr(Ni,Ge)_2-x, crystallizes with the hexagonal AlB₂ structure type, Pearson symbol hP3, space group P6/mmm. The refinement on X-ray powder diffraction data led to the composition PrNi_0.42Al_0.06Ge_1.34(2) with 9 % vacancies on the 2-fold site inside the trigonal prisms, a = 4.1622(1), c = 4.2157(2) Å (R_p = 0.0212, R_wp = 0.0265, R_B = 0.0742), whereas the composition of the single crystal refined to Pr(Ni_0.23Al_0.03Ge_0.74)_2.00(1) (a = 4.156(1), c = 4.209(2) Å, R = 0.0275, wR = 0.0516), when the Ni:Al:Ge ratio was fixed to the value found by the EDX analysis.

Crystal structure of Pr(Ni,Al,Ge)_2-x (AlB₂ structure type).

Keywords

Praseodymium / Nickel / Alumogermanide / X-ray powder diffraction / X-ray single-crystal diffraction / Crystal structure