Ein neuer Bautyp zur Formel Me²⁺M₂³⁺O₄ Die Kristallstruktur von SrCr₂O₄

Abstract

Einkristalle von SrCr2O4 wurden dargestellt und die Kristallstruktur mit Diffraktometer‐Röntgendaten bestimmt: a = 11,643; b = 5,881 und c = 5,115 Å, Raumgruppe D 2h13–Pmmn. SrCr2O4 stellt einen neuen Bautyp dar, mit Cr3+ in oktaedrischer und Sr2+ in trigonal prismatischer Umgebung von O2−.

Spinel to CaFe2O4 Transformation: Mechanism and Properties of β-CdCr2O4

“…CdCr 2 O 4 crystallizes in the cubic spinel structure, similar to MgCr 2 O 4 and ZnCr 2 O 4 . Other chromites(III) crystallize either in a SrCr 2 O 4 -type structure (like SrCr 2 O 4 itself, BaCr 2 O 4 , or α-CaCr 2 O 4 ) or in the CaFe 2 O 4 -type structure (such as the β-CaCr 2 O 4 polymorph). In each of these compounds, the [Cr−O 6 ] octahedra are connected in different ways, and this contributes to the differences in their physical properties.…”

Increasing the Structural Complexity of Chromium(IV) Oxides by High-Pressure and High-Temperature Reactions of CrO2

“…This is frequently found in misfit-layer cobalt compounds and would imply a valence lower than 4+. Nevertheless, in the case of SrCr 2 O 4 ( IV Cr 3+ ), which present the same type of [Cr−O 2 ] layers, the ⟨Cr−O⟩ distance is 2.045 Å, larger than the expected value for Cr 3+ , avoiding too short ⟨O−O⟩ distances in this layer type.…”

Torque equilibrium spin wave theory of Raman scattering in an anisotropic triangular lattice antiferromagnet with Dzyaloshinskii-Moriya interaction

“…T N (K) Space group Q Ba 3 CoSb 2 O 9 [21,49,50] 3.8 P6 3 /mmc (2/3,0,1) CuCrO 2 [51,52] 24.2 R 3m (0.658,0,0) α-SrCr 2 O 4 [17,53] 43 Pmmn (0.6609,0,1) α-GaCr 2 O 4 [16,54] 43 Pmmn (0.6659,0,1) LuMnO 3 [22] 90 P6 3 cm (2/3,0,0) Cs 2 CuCl 4 [20,47,55] 0.62 Pnma (0.530,0,0) [20] Cs 2 CuBr 4 [55][56][57] 1.4 Pnma (0.575,0,0)…”