Leonhard Y Dorsch, Nikolai Haferkorn, Jasper A Baldauf, Marvin Michak, Thomas C Hansen, Rainer Pöttgen, Holger Kohlmann
The hydrogenation behavior of FeB type CeGe was investigated. Hydrogenation (deuteration) produces mixtures of two modifications, similar to hydrides of other FeB type phases LnTt (Ln = La, Ce, Nd; Tt = Si, Ge). P-CeGeD0.75(2) (Pnma, a = 8.1603(5) Å, b = 4.0938(3) Å, c = 6.2911(4) Å) crystallizes in the LaGeH structure type (filled FeB type), whereas C-CeGeD0.95(3) (Cmcm, a = 4.2958(2) Å, b = 11.9970(7) Å, c = 4.0885(3) Å) crystallizes in the ZrNiH structure type (filled CrB). Similar to CeSiHx the mixtures feature exceptionally high ferromagnetic ordering temperatures of 21.6(1) K for CeGeDx and 22.1(2) K for CeGeHx (x ≤ 1), with the effective magnetic moments of 2.44(1) μB (CeGeDx) and 2.38(1) μB (CeGeHx) being close to the free ion value of 2.54 μB of Ce3+. The hydrides (deuterides) were studied by neutron powder diffraction (NPD), thermal analysis and magnetic susceptibility measurements.