Mössbauer Study of Some 2–17 Lanthanide-Iron Compounds

We have studied the iron-rich, rare-earth-iron intermetallic compounds R2Fe17 (R = Pr, Gd, Tm, Lu), using the Mössbauer effect in 57Fe. The measured average hyperfine field H(T/Tc) acting on the 57Fe nuclei is a unique, monotonically decreasing function of T/Tc, with no observed irregularity at temperatures corresponding to a suspected ferromagnetic-antiferromagnetic phase transition in these compounds. The onset of paramagnetism occurs at temperatures close to the upper transition points measured by Strnat et al., namely at Tc = 282°, 472°, 271°, and 263°K for Pr2Fe17, Gd2Fe17, Tm2Fe17, and Lu2Fe17, respectively. Low-temperature (≃90°K) spectra indicate the presence of at least four magnetically nonequivalent Fe sublattices, while for T>Tc broadened 2-line absorption spectra typical of 57Fe at noncubic sites in paramagnetic material are observed.