Neutron powder diffraction study of the ternary RMgSn (R=Ce–Nd, Tb–Tm, Yb) compounds
Résumé
The ternary intermetallic RMgSn compounds are studied by neutron powder diffraction. The CeScSi-type PrMgSn and NdMgSn compounds present a commensurate antiferromagnetic structure, while the (Tb–Tm)MgSn are characterized by an incommensurate sine-wave modulated magnetic structure, which can tend to a square-modulated arrangement at low temperature due to appearance of higher odd integer harmonics. The TiNiSi-type CeMgSn compound is also characterized by an incommensurate sine-wave modulated magnetic structure, while PrMgSn exhibits a ferromagnetic arrangement with a canting at low temperature. Finally, the ZrNiAl-type YbMgSn compound evidences no magnetic ordering. These results are discussed and compared with those published for the other CeScSi-type compounds.