High-pressure high-temperature preparation of CeGe${}_3$

The metastable compound CeGe${}_3$ was obtained by high-pressure high-temperature synthesis from pre-reacted Ce and Ge at 3 GPa of pressure and 1873 K, with subsequent annealing over several hours at 1173 K. The product crystallises in a 2 × 2 × 2 superstructure of the cubic Cu${}_3$Au-type structure with space group Fm$\overline{3}$m and a = 8.6970(2) Å. CeGe${}_3$ decomposes at 520(10) K into CeGe${}_{2-x}$ and elemental Ge.