Crystal structure of the compound Pr₄Ge₇

Chem. Met. Alloys 2 (2009) 115-122

https://doi.org/10.30970/cma2.0102

Oleh SHCHERBAN, Igor SAVYSYUK, Nataliya SEMUSO, Roman GLADYSHEVSKII, Karin CENZUAL

The structure of the binary germanide Pr₄Ge₇ has been determined by single-crystal X-ray diffraction on a twinned crystal. It is an ordered vacancy derivative of the α-ThSi₂ type, Pearson symbol oS44, space group C222₁, a = 6.007(2), b = 13.987(4), c = 12.009(4) Å, isotypic to the structure reported earlier for Nd₄Ge₇. The cell parameters of seven other praseodymium germanides observed in samples annealed at 873 K were refined from powder X-ray diffraction data.

Cell parameters corresponding to the α-ThSi₂ type and homogeneity ranges of the non-stoichiometric praseodymium digermanides Q₂ and Q₁.

Keywords

Germanide / Praseodymium / Single-crystal X-ray diffraction / Crystal structure / Vacancy derivative