155Gd Mössbauer spectroscopy measurements on Gd2T17C x,with T=Fe,Co, Ni andx varying from 0.6 to 1.2

¹⁵⁵Gd Mössbauer measurements were performed on Gd₂T₁₇C _x with T=Fe, Co, and Ni andx varying from 0.6 to 1.2. The crystal structures of these compounds are either the Th₂Zn₁₇ or the Th₂Ni₁₇ structure type. There is only partial occupation of the site available to the carbon atoms, leading to several crystallographically non-equivalent gadolinium surroundings. These various Gd sites show different quadrupole interactions. Doping with carbon causes an increased Curie temperature for the Gd₂Fe₁₇C _x compounds. The randomness of the occupation by carbon has been studied.