A Sn119 Moessbauer study of RE6M13Sn (RE=La,Pr,Nd; M=Fe,Co) and their hydrides

119Sn and 57Fe Moessbauer studies are reported for various RE6Fe13X compounds, isostructural La6Co13Sn, and some of their hydrides. The 119Sn studies prove that Sn exclusively occupies a single lattice site (4a). At 4.2 K a transferred magnetic hyperfine field of about 5 T is present which at room temperature is reduced to 2.5 T. This result clarifies the open questions concerning the 197Au spectra from Pr(Nd)6Fe13Au and justifies the conclusions drawn earlier that this pattern is due to a magnetic hyperfine interaction. Spectra of hydrides indicate that the transferred hyperfine field on the Sn site is little affected by the uptake of hydrogen, unlike the 57Fe hyperfine field. From the 57Fe results an information is gained about the Fe site occupation and the specific easy axis of magnetization in a given sample. Comparing magnetization and hyperfine field data as a function of temperature, a complex spin structure in the majority of the compounds under investigation is suggested. (orig.)