Cs2Ln3CuS8 (Ln = La-Nd, Sm-Tb): Synthesis, Crystal Structure, and Magnetic and Optical Properties

Tatiana A Pomelova; Charlène Delacotte; Natalia V Kuratieva; Pierric Lemoine; Stéphane Cordier; SangJun Park; Thierry Guizouarn; Vincent Pelletier; Regis Gautier; Nikolay G Naumov

doi:10.1021/acs.inorgchem.2c03447

Cs₂Ln₃CuS₈ (Ln = La-Nd, Sm-Tb): Synthesis, Crystal Structure, and Magnetic and Optical Properties

Inorg Chem. 2023 May 1;62(17):6586-6597. doi: 10.1021/acs.inorgchem.2c03447. Epub 2023 Apr 18.

Affiliations

¹ Nikolaev Institute of Inorganic Chemistry SB RAS, 3, Akad. Lavrentiev Ave., 630090 Novosibirsk, Russian Federation.
² Univ Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR-UMR 6226, F-35000 Rennes, France.
³ Novosibirsk State University, 2, Pirogova Str., 630090 Novosibirsk, Russian Federation.

PMID: 37070741
DOI: 10.1021/acs.inorgchem.2c03447

Abstract

This work reports the preparation of new quaternary sulfides Cs₂Ln₃CuS₈ (Ln = La-Nd, Sm-Tb), their original crystal and electronic structures, and their magnetic properties. The sulfides were prepared using a reactive flux method from mixtures of Ln₂S₃ (EuS), Cs₂S₆, Cu₂S, and S. They crystallize in a new type of structure (C2/m space group) and exhibit a layer-like crystal structure, which is a hybrid of those of the ACe₂CuS₆ series (A = Cs, K) and that of K₂CeCu₂S₄. The values of the optical band gap calculated by the Kubelka-Munk equation are in the range of 1.2-2.62 eV depending on the nature of the Ln ion. The Cs₂Gd₃CuS₈ compound displays relatively great magnetic refrigerating properties at cryogenic temperature with the mass entropy change (-ΔS_M) reaching 19.5 J kg^-1 K^-1 at 3.5 K for ΔH = 5 T.