Co₃(SeO₃)(SO₄)(OH)₂: A Selenite-Sulfate Compound with a Distorted Kagomé Lattice

Abstract

A new selenite-sulfate compound Co 3 (SeO 3 )(SO 4 )-(OH) 2 was prepared using a typical hydrothermal reaction. This compound is found to crystallize in an orthorhombic space group of Pnma, featuring a 2D distorted kagoméstructure composed of linear and zigzag Co-chains, in which the magnetic ions construct different isosceles-triangles. Our results of magnetic and specific heat measurements confirm a canted antiferromagnetic order at T N ∼ 29 K. Further, the successive field-induced metamagnetic transitions can be observed at H c1 ∼ 1 T, H c2 ∼ 23 T, and H c3 ∼ 27 T, respectively. A clear magnetic hysteresis loop with a coercive field (H c ) of ∼1.4 T is also observed.

“Stagomé” Lattice: The Missing Member of the Star-Kagomé Family

“…The effective paramagnetic moment μ eff = 5.23 μ B calculated from the slope is much larger than the theoretical value of 3.87 μ B for a high-spin Co II ion ( S = 3 / 2 , g = 2) owing to the spin–orbit coupling. Comparable μ eff values have been reported in Co II -based kagomé compounds Co 3 (SeO 3 )­(SO 4 )­(OH) 2 (5.16 μ B ) and Co 3 V 2 O 8 (5.10 μ B ) . A magnetic transition with an onset temperature of about 10 K is evident in the χ M vs T plot (Figure b).…”

“…According to the Goodenough–Kanamori rule, whether the exchange interaction is ferromagnetic (FM) or antiferromagnetic (AFM) depends on the coordination geometry surrounding the metal centers . It is well-known that FM (AFM) interactions have been observed in several cobalt oxide phases with Co–O–Co angles less (greater) than 100°. ,, Furthermore, exchange pathways involving only three atoms (Co–O–Co) are more dominant than those including four or more (Co–O···O–Co). With angles well above 100°, J T1 [∠Co1–O5­(H)–Co2 = 114.59(5)°] and J T3 [∠Co2–O5­(H)–Co3 = 118.49(5)°] are considered as AFM interactions.…”

Hg2(SeO3)(SO4): the first sulfate selenite with large birefringence explored from d10transition metal compounds

“…However, as far as we know, only four metal sulfate selenites have been reported: Cu 4 (SeO 3 )(SO 4 )(OH) 4 (H 2 O) 2 and Pb 1.93 Cu 1.89 (Se 0.85 S 0.15 O 3 )(SO 4 )(OH) 4 are natural minerals, and K 8 (SeS 3 Mo 6 O 33 )(H 2 O) 5.5 and Co 3 (SeO 3 )(SO 4 )(OH) 2 are synthetic compounds. 23–26 No d 10 transition metal (TM) sulfate selenites have been reported. The d 10 -TMs are beneficial for improving the birefringence of crystals due to their high polarizability and deformability.…”

A cascade of magnetic phase transitions and a 1/3-magnetization plateau in selenite–selenate Co3(SeO3)(SeO4)(OH)2 with kagomé-like Co2+ ion layer arrangements: the importance of identifying a correct spin lattice

“…The crystal structure of Co 3 (SeO 3 )(SeO 4 )(OH) 2 is very similar to that of the related sulfate compound Co 3 (SeO 3 )(SO 4 )(OH) 2 . 17 As in Co 3 (SeO 3 )(SeO 4 )(OH) 2 , the Se site of SeO 3 in Co 3 (SeO 3 ) (SO 4 )(OH) 2 is split to a much lesser extent (0.9389 vs. 0.0611) than in Co 3 (SeO 3 )(SeO 4 )(OH) 2 (0.856 vs. 0.144). The S site of SO 4 in Co 3 (SeO 3 )(SO 4 )(OH) 2 , which corresponds to the Se site of Se1O 4 , is not split.…”

“…The magnetic properties of Co 3 (SeO 3 )(SeO 4 )(OH) 2 differ from those of the sulfur analogue Co 3 (SeO 3 )(SO 4 )(OH) 2 . 17 The latter undergoes only one temperature-induced transition at T N = 29 K, but three successive metamagnetic transitions at ∼1, ∼23 and ∼27 T. This difference may reflect the fact that the SeO 3 groups interlink between adjacent octahedral chains to form layers in both compounds, but the interlayer linking is done by the SO 4 groups in Co 3 (SeO 3 )(SO 4 )(OH) 2 but by the SeO 4 groups in Co 3 (SeO 3 )(SeO 4 )(OH) 2 . Thus, the substitution of the SO 4 group for the SeO 4 group would have a greater effect on the interlayer than on the intralayer spin exchanges.…”