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Ternary rare earth silicides RE2M3Si4 (RE = Sc, Y, Lu; M = Mo, W): crystal structure, coloring and electronic
Morten B Nielsen1, Weiwei Xie2, Robert J Cava2
1Center for Materials Crystallography, Department of Chemistry, Aarhus University, 8000 Aarhus C, Denmark. mbnielsen@chem.au.dk and Department of Chemistry, Princeton University, Princeton, 08540 NJ, USA.
Abstract:
The ternary compounds Sc2Mo3Si4, Y2Mo3Si4, Lu2Mo3Si4 and Sc2W3Si4 have been synthesized using arc melting and structurally characterized using single crystal X-ray diffraction. The compounds are isostructural with Gd5Si4 but with coloring (order of the rare earth and transition metals) on the Gd site. In contrast to group 4 and 5 ternaries of the same type, we observe no site mixing between the rare earth and transition metals. The Y compound displays a different, less common coloring from the others and through DFT calculations and investigation of the solid solution between Sc2Mo3Si4 and Y2Mo3Si4 it is shown that the different coloring of the latter is only marginally more stable. The electronic structures of the ternary compounds have been investigated using DFT calculations, yielding densities of states very similar to Gd5Si4. These predict metallic behavior and no magnetism, which is confirmed through resistivity and magnetization measurements.
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