 | Acta Crystallographica Section B Acta Crystallographica Section B STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS |
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![[Figure 2]](lo5069fig2mag.jpg)
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Figure 2
R–T diagram of the RSi2 and R2TSi3 compounds. (a) normalized lattice parameter a, (b) normalized lattice parameter c, (c) normalized ratio c/a of lattice parameters, (d) shortest Si—T bonds, (e) ratio of atomi radii rT,Si/rR, (f) electronegativity difference EN(Si,R), (g) range of ordering, (h) thermal treatment, (i) density and (j) valence electron concentration. The used markers symbolize the crystal system: hexagon — hexagonal AlB2-like systems, open star — orthorhombic, AlB2-like systems, diamond — tetragonal ThSi2 systems, elongated diamond — orthorhombic GdSi2 systems. The lattice parameters a and c of the subplots (a) and (b) are normalized to the R–R distances within a/b and along c, respectively, to provide comparability. Accordingly, the ratio c/a in subplot (c) is also based on these normalizations. The shortest Si/T bonds in subplot (d) are calculated based on the formula (1) ![[link]](../../../../../../logos/arrows/b_arr.gif) . Subplot (e) depicts the ratio of atomic radii qrad, which is based on equation (2). Subplot (f) shows the electronegativity difference for the evaluation of the Zintl conditions. For the range of ordering n in subplot (g), a structure with disordered Si/T sites is marked with a black symbol, otherwise the color stands for the range of ordering n. For the thermal treatment (h), the color represents the temperature and the circle size the time of the treatment (triangle if unknown). Application of the floating zone method is marked with a black dot •, while no treatment is marked with a cross ×. The plots for the theoretical properties vec and ratio of radii were completed for not experimentally determined compounds (small circles) (Riedel & Janiak, 2011). |
![[Figure 2]](lo5069fig2.jpg)
| STRUCTURAL SCIENCE CRYSTAL ENGINEERING MATERIALS |
ISSN: 2052-5206
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