Synthesis, crystal structure, and magnetic properties of layered SmCrS2−xSexO solid solutions

Abstract

Layered oxychalcogenides namely the SmCrS_2−xSe_xO (x = 0–2) solid solutions, were synthesized via high-temperature solid-state reactions. SmCrQ₂O (Q = S, Se) crystallizes in the monoclinic space group of C2/m (No. 12), featuring typical layered structures. The two-dimensional (2D) ²_∞[CrQ₂O]³⁻ motifs stack along the a axis, which are separated by Sm³⁺ ions. The ²_∞[CrQ₂O]³⁻ layers are composed of [CrQ₆]⁹⁻ and [CrQ₄O₂]⁹⁻ octahedra via corner and edge sharing. The in-plane Cr atoms feature a distorted honeycomb arrangement with prolonged Cr⋯Cr distances along the c axis. The powder X-ray diffraction results confirm the phase purities and the formation of solid solutions. Magnetic measurements indicate that the SmCrS_2−xSe_xO solid solutions show typical antiferromagnetic ordering. The Néer temperatures (T_N) increase from 74 K to 121 K with the decrease in S content.