57Fe mössbauer investigation of carbides Gd2Fe17Cx

Abstract The compounds Gd 2 Fe 17 C x have been prepared by arc melting for x ⩽ 1 and by melt spinning for x > 1. 57 Fe Mossbauer experiments have been used to study these compounds. The spectra have been analysed in terms of seven subspectra by assuming a subdivision of the 18 f , 18 h and 9 d sites into two groups with a relative intensity ratio of 1:2. It is found that the effective hyperfine fields H eff at 12 K do not change much with C content x , while the H eff values at 293 K show a strong increase for small C content. The average isomer shifts (IS) increase with C content and the values of Δ(IS)/Δ(ln V ) are close to the typical value of 1.0 mm s −1 for a close-packed structure.