Magnetic and electrical properties of Sc(M1−xSix)2−y (M=Fe, Co, Ni)

On the ternary Laves phases {Sc,Ti}2M3Si (M=Cr, Mn, Fe, Co, Ni) with MgZn2-type

“…X-ray diffraction and EPMA of the alloy annealed at 800 • C revealed that this composition is a mixture of Laves phase with ScNi 2 (MgCu 2 -type; space group: Fd3m, a = 0.69404(1) nm) and G phase (Th 6 Mn 23 -type; space group: Fm3m, a = 1.22265(2) nm). Sc 2 Fe 3 Si and Sc 2 Co 3 Si annealed at 800 • C were found to be single phase with MgZn 2 -type structure in good agreement with previous investigations [10,11,14]. Rietveld refinements ( Table 2) confirm for both compounds the MgZn 2 -type structure with a complete occupancy at the 4f sites by Sc atoms and a random distribution of Fe (or Co) and Si atoms at the 2a and 6h sites.…”

“…Rietveld refinements ( Table 2) confirm for both compounds the MgZn 2 -type structure with a complete occupancy at the 4f sites by Sc atoms and a random distribution of Fe (or Co) and Si atoms at the 2a and 6h sites. Results on the lattice parameters and site preference for Sc 2 Fe 3 Si agree well with data in literature [10,11,14], and reasonable agreement was obtained for positional parameters (see Tables 1 and 2). In contrast to that, the crystallographic model with ordered distribution of the M and Si atoms in the 2a and 6h sites yielded high residual values and negative temperature factors (values in square brackets, Table 2) and thus was rejected.…”

“…1). Sc 2 Ni 3 Si is a ternary Laves phase [10,11,14]. X-ray diffraction and EPMA of the alloy annealed at 800 • C revealed that this composition is a mixture of Laves phase with ScNi 2 (MgCu 2 -type; space group: Fd3m, a = 0.69404(1) nm) and G phase (Th 6 Mn 23 -type; space group: Fm3m, a = 1.22265(2) nm).…”

Magnetic and structural properties of Sc(Fe1−xSix)2 Laves phases studied by Mössbauer spectroscopy and neutron diffraction

“…7. The points for x = 0.06 and 0.25 are taken from a paper [14] in which T C is determined from ac-susceptibility measurements. Curie temperature monotonically decreases from 650(5) K for ScFe 2 to about 90 K for x = 0.30.…”

“…Fe mean hyperfi ne magnetic fi elds temperature dependences. The T C temperatures for samples with x = 0.06 and 0.25 are taken from a paper [14] in which T C are determined from ac-susceptibility measurements. The dashed line is a guide for eyes.…”