Structural and magnetic properties of the new Yb1-xScxMn6Sn6 solid solution

Abstract

We have investigated the crystal and magnetic properties of the new Yb1-xScxMn6Sn6 compounds (0.00 ≤ x ≤ 1.00). X-ray diffraction experiments show that all samples are isotypic with HfFe6Ge6 and the lattice constants shrink upon increasing the Sc content. The lack of anomaly in the composition dependence of the cell parameters indicates that Yb remains strongly intermediate valent (ʋYb ∼ 2.6–2.7) as in the YbMn6Sn6 parent compound (ʋYb ∼ 2.6). As a result, Yb does not magnetically order and the magnetism arises exclusively from the Mn sublattice. The Sc-doping yields a moderate increase of the ordering temperatures (<380 K). While YbMn6Sn6 is a simple ferromagnet (TC = 284 K), a low-temperature antiferromagnetic-like state, whose temperature extent increases with the Sc content, is stabilized. It manifests through a sign change of the magnetocaloric effect. The alloys with x = 0.90 and 1.00 are antiferromagnetic-like over the whole ordered temperature range. Low-field metamagnetism is evidenced in the antiferromagnetic-like state. The results are discussed and compared with previously published data.