The R MgSn 2 Series of Compounds ( R = Rare Earth Metal): Synthesis, Crystal Structure, and Magnetic Measurements

The novel isostructural series of phases R MgSn 2 ( R = Y, La–Nd, Sm, Gd–Tm, Lu) is presented. They were prepared by direct synthesis in an induction furnace and subsequently annealed at 500 °C. Their crystal structures were determined through single‐crystal X‐ray diffraction analysis of the Ce representative [ I 4 2 m, tI 32‐LaMgSn 2 , Z = 8, a = 0.82863(3) nm, c = 1.23129(5) nm] and confirmed by powder X‐ray diffraction analysis of the other members of the series. Rietveld refinements were also performed on the homologues with R = Pr, Tm, and Y. The title phases show a unique space distribution of atoms, characterized by the presence of a Sn–Sn dumbbell distanced at around 0.29 nm. Their structures are related to those of a few binary AeTt 3 ( Ae = alkaline earth; Tt = Si, Ge; I 4/ mmm , tI 32‐YbSi 3 ) compounds that are stable at high pressure, characterized by a more complex 3D covalently bonded Tt network. Compounds CeMgSn 2 and TbMgSn 2 were magnetically characterized; they show paramagnetic behavior with the presence of ferromagnetic interactions, more pronounced in the case of TbMgSn 2 , as suggested by the Curie–Weiss temperatures, determined in the high‐temperature range, of 0.96 and 27.6 K for CeMgSn 2 and TbMgSn 2 , respectively.