Synthesis and Characterization of Oxide Chloride Sr₂VO₃Cl, a Layered S = 1 Compound

Abstract

The mixed-anion compound with composition Sr2VO3Cl has been synthesized for the first time, using the conventional high-temperature solid-state synthesis technique in a closed silica ampule under inert conditions. This compound belongs to the known Sr2 TmO3Cl (Tm = Sc, Mn, Fe, Co, Ni) family, but with Tm = V. All homologues within this family can be described with the tetragonal space group P4/nmm (No. 129); from a Rietveld refinement of powder X-ray diffraction data on the Tm = V homologue, the unit cell parameters were determined to a = 3.95974(8) and c = 14.0660(4) Å, and the atomic parameters in the crystal structure could be estimated. The synthesized powder is black, implying that the compound is a semiconductor. The magnetic investigations suggest that Sr2VO3Cl is a paramagnet at high temperatures, exhibiting a μeff = 2.0 μB V–1 and antiferromagnetic (AFM) interactions between the magnetic vanadium spins (θCW = −50 K), in line with the V–O–V advantageous super-exchange paths in the V–O layers. Specific heat capacity studies indicate two small anomalies around 5 and 35 K, which however are not associated with long-range magnetic ordering. 35Cl ss-NMR investigations suggest a slow spin freezing below 4.2 K resulting in a glassy-like spin ground state.

Ca2MnO3X (X = Cl, Br) Oxyhalides with 1-Dimensional Ferromagnetic Chains of Square-Planar S = 2 Mn3+

“…This is due to the large differences in size and polarizability between the two anionic species (Hume–Rothery rules) . For example, the substitution of chloride for oxide in materials adopting the n = 1 Ruddlesden–Popper (RP) structure type tends to result in oxychloride materials where the Cl – anions replace the apical oxides in an ordered fashion, as shown in the structures of Sr 2 M 3+ O 3 Cl (M = V, Mn, Fe, Co, and Ni) and Ca 2 Fe 3+ O 3 Cl. − Further substitution results in the replacement of the remaining apical oxide as shown by the structures of A 2 Cu 2+ O 2 Cl 2 (A = Ca, Sr) and Sr 2 Co 2+ O 2 Cl 2 . ,, …”

“…21 For example, substitution of chloride for oxide in materials adopting the n = 1 Ruddlesden-Popper (RP) structure type tends to result in oxychloride materials where the Clanions replace the apical oxides in an ordered fashion as shown in the structures of Sr2M 3+ O3Cl (M = V, Mn, Fe, Co, and Ni) and Ca2Fe 3+ O3Cl. [2][3][4][5][6][7] Further substitution results in the replacement of the remaining apical oxide as shown by the structures of A2Cu 2+ O2Cl2 (A = Ca, Sr) and Sr2Co 2+ O2Cl2. 8,9,22 The Ca 2+ cation is too small to be properly accommodated in the A sites of the RP structure without a structural distortion.…”

“…There are a large number of known oxyhalide materials with the general formula Sr 2 M 3+ O 3 X (M = V, Mn, Fe, Co, Ni) with structures based on the n = 1 Ruddlesden–Popper (RP) structure type. In these materials, the chloride or bromide anions preferentially occupy the apical sites in an ordered fashion, and they are typically antiferromagnetic insulators due to the 180° M–O–M superexchange interaction within each layer. − …”

“…In these materials, the chloride or bromide anions preferentially occupy the apical sites in an ordered fashion, and they are typically antiferromagnetic insulators due to the 180 ° M-O-M superexchange interaction within each layer. [2][3][4][5][6][7][8][9] This tendency can be overcome by using ions with particular radius or coordination constraints. For example, the A3Fe2O5Cl2 series of phases adopt structures analogous to the n = 2 RP phases with apical chlorides for A = Ca and Sr, while for A = Ba, the structure contains a complex network of corner-sharing FeO4 tetrahedra.…”

Pinalites: Optical Properties and Quantum Magnetism of Heteroanionic A3MO5X2 Compounds

“…Several compounds are known in which one halogen and five oxygen atoms coordinate to a metal atom in a square-pyramidal configuration, similar to CROC. The most diverse compounds are A 2 M 3+ O 3 X, which are analogues of K 2 NiF 4 -type layered perovskites, where A = Sr and Ca, M = Sc, V, Mn, Fe, Co, and Ni, and X = F, Cl, and Br. ,− See ref for oxyfluorides with related layered perovskite structures. The magnetic properties of the materials have also been investigated.…”