Syntheses, Crystal Structures, and Optical and Magnetic Properties of Some CsLnCoQ₃ Compounds (Ln = Tm and Yb, Q = S; Ln = Ho and Yb, Q = Se)

Abstract

The four new compounds CsTmCoS3, CsYbCoS3, CsHoCoSe3, and CsYbCoSe3 have been synthesized at 1123 K. These black‐colored isostructural compounds crystallize in the KZrCuS3 structure type with four formula units in space group Cmcm of the orthorhombic system. The structure of these compounds is composed of $^{2}_{\infty}\rm [LnCoQ_{3})^{-}]$ layers separated by Cs atoms. Because there are no Q–Q bonds, the formal oxidation states of Cs/Ln/Co/Q are 1+/3+/2+/2−, respectively. CsHoCoSe3 shows paramagnetic behavior with μeff = 11.9(1) μB, whereas CsYbCoS3 displays an antiferromagnetic‐like transition at ∼2.7 K with μeff = 5.85(1) μB. Both CsYbCoS3 and CsYbCoSe3 exhibit optical band gaps in the near infrared region and broad absorption bands at lower energies.

Syntheses, structures, and optical properties of Ba4Ga4SnSe12and Ba6Ga2SnSe11

“…All atoms lie at general positions 4e. The Ga and Sn atoms are coordinated to a distorted tetrahedron of four Se atoms with Ga-Se distances ranging from 2.358 (1) to 2.496 (1) Å and Sn-Se distances ranging from 2.479 (5) to 2.968 (7) Å which are comparable to the Ga-Se and Sn-Se bond lengths observed in BaGa 4 Se 7 (2.361 to 2.488 Å for Ga-Se) 50 and Ba 6 Sn 6 Se 13 (2.508 to 3.268 Å for Sn-Se) 35 respectively, while the Ba atoms have three different kinds of coordination geometry. The Ba1, Ba3, Ba4, and Ba5 atoms are eight-coordinated to Se atoms in a distorted bicapped trigonal prismatic geometry with the Ba-Se distances ranging from 3.166 (1) to 3.775 (1) Å, which are in agreement with those of 3.244 to 3.801 Å in Ba 2 InErSe 5 ; 28 while the Ba 2 atoms are coordinated with nine Se atoms in a distorted tricapped trigonal prismatic geometry with the Ba-Se distances ranging from 3.266(1) to 3.746(1) Å, which are close to those in BaLaSb 2 Se 6 (3.2604 to 3.8079 Å), 51 whereas the Ba 6 atoms are coordinated to a distorted monocapped trigonal prism of seven Se atoms with the Ba-Se distances ranging from 3.110(1) to 3.582(1) Å, which are comparable to those of 3.228 to 3.769 Å in Ba 6 Sn 6 Se 13 .…”

“…Over the past few decades, chalcogenide semiconductors possessing multi-cations have received great attention owing to their amazing structural and compositional complexity and fascinating physical properties, including magnetic, superconducting, thermoelectric, electrical, and nonlinear optical properties. For example, the new layered compound CsHgInS 3 has a γ-ray attenuation length comparable to commercial Cd 1−x Zn x Te, indicating promising properties for X-ray and γ-ray detection; 1 the Bi-Bi bond containing compound CsBi 4 Te 6 exhibits attractive thermoelectric properties with a thermoelectric figure of merit of ∼0.8 at a temperature of 225 K when doped appropriately; 2 ALnMQ 3 (A = Rb, Cs; Ln = rare-earth metal; M = Mn, Co, Zn, Cd, Hg; Q = S, Se, Te) offers flexibility in band gap engineering by controlling the composition and crystal orientation; [3][4][5][6][7] Ba 8 Hg 3 U 3 S 18 contains interesting infinite chains of US 6 octahedra and nearly linear [S-Hg-S] 2− dithiomercurate anions; 8 Cs 5 BiP 4 Se 12 , 9 Rb 3 Ta 2 AsS 11 , 10 La 4 InSbS 9 , 11 Sm 4 GaSbS 9 , 12 LiAsS 2 , 13 and γ-NaAsSe 2 14 exhibit very strong second harmonic generation (SHG) responses in the IR range, indicating their potential use in laser frequency conversion applications; copper-based quaternary chalcopyrite semiconductors Cu 2 ZnMQ 4 (N = Ge, Sn; Q = S, Se) have large photoelectric responses, indicating that they are promising candidates for photovoltaic applications. [15][16][17] In one of our earlier studies, we explored the quaternary A/M/M′/Q (A = alkaline-earth metal; M = Al, Ga, In; M′ = Si, Ge; Q = S, Se, Te) system and found four isostructural compounds, BaGa 2 MQ 6 (M = Si, Ge; Q = S, Se), which were characterized to be a new series of IR nonlinear optical materials showing promise for practical applications.…”

New Quaternary Rare-Earth Chalcogenides BaLnSn2Q6 (Ln = Ce, Pr, Nd, Q = S; Ln = Ce, Q = Se): Synthesis, Structure, and Magnetic Properties

“…Rare-earth chalcogenides have exhibited not only rich structures resulting from the diverse geometry of the Ln -centered coordination polyhedra and the flexible connectivity among them, but also fascinating magnetic, transport, and optical properties related to the 4f electrons. , Recently, rare-earth chalcogenides that also contain the p-block main group elements have received increasing attention. − Among them, Na 1.515 EuGeS 4 contains a three-dimensional (3D) framework structure with empty nanotubules constructed by mixed valence Eu (II/III) cations; K 2 Ln 2 As 2 Se 9 ( Ln = Sm, Gd) is the first series of quaternary rare-earth selenoarsenate compounds with a 3D framework containing chairlike As 2 Se 4 units; ZnY 6 Si 2 S 14 , Y 3 GaS 6 , La 2 Ga 2 GeS 8 , Eu 2 Ga 2 GeS 7 , La 4 GaSbS 9 , and Ba 2 YInS 5 show strong second-harmonic generation (SHG) responses in the middle IR. In earlier studies, we carried out systematic investigation in the quaternary A/M/ Ln /Q (A = alkaline-earth metal; M = group IIIA metals Ga or In; Ln = rare-earth element; Q = chalcogen) system, hoping that the introduction of alkaline-earth metal would help to increase the band gap and hence to increase the laser damage threshold for IR nonlinear optical (NLO) materials and avoid the two-photon absorption of the conventional 1 μm pumping source.…”

Ba3LnInS6 (Ln = Pr, Sm, Gd, Yb) and Ba2LnGaS5 (Ln = Pr, Nd): Syntheses, Structures, and Magnetic and Optical Properties

“…Interest in rare-earth chalcogenides originates not only from their rich structures as a result of the diversity in the geometry of the Ln-centered coordination polyhedra and the connectivity between them but also from the important physical properties related to the 4f electrons. , In recent years, extensive exploratory synthesis has led to the discovery of many new multinary rare-earth chalcogenides exhibiting interesting structures and physical properties. − For example, CsCu 3 Dy 2 S 5 and CsCu 3 Er 2 S 5 have an isotypic three-dimensional network 3 ∞ [Cu 3 M 2 S 5 ] − , spreading along the a axis with large channels, that is well-suited to take up the highly coordinated Cs + cations; KCuCe 2 Se 6 has an interesting structure consisting of two-dimensional 2 ∞ [CuCe 2 Se 6 ] − layers with orderly arranged Cu atoms; in the compounds BaLn 2 FeS 5 (Ln = Ce, Pr, Nd, Sm), the Fe 2+ ion exhibits an antiferromagnetic ordering at around 40 K, and AgPb m LaTe m +2 shows high electrical conductivity and a relatively small Seebeck coefficient …”