High-Pressure Synthesis and Structures of New Barium Chromium Sulfides, BaCr4S7 and Ba2Cr5S10, with New Type Face-Sharing CrS6 Structure Units

Abstract

Two new ternary barium chromium sulfides, BaCr 4 S 7 and Ba 2 Cr 5 S 10 , were synthesized by reactions of barium sulfide, sulfur, and chromium metal under high-pressure and high-temperature conditions. Single crystals of BaCr 4 S 7 were obtained from a starting mixture with a molar ratio of Ba:Cr:S = 2:5:10 after reacting at 1200 C and under a pressure of 5 GPa. It crystallizes in the monoclinic space group P2 1 =c (No. 14) with a ¼ 6:739ð4Þ Å , b ¼ 22:665ð9Þ Å , c ¼ , V ¼ 683:1ð9Þ Å 3 , and Z ¼ 2. The structure is composed of CrS 2 sheets and the wall-shaped subunits, like as in BaCr 4 S 7 , but the subunits do not connect the adjacent CrS 2 sheets. It has a two-dimensional structure, and Ba atoms are situated in interlayer regions.

High-Pressure Synthesis and Crystal Structure of the Sulfur-Richest Chromium Sulfide CrS3 Composed of Cr(III) and Disulfide Ions

“…In the Ba−Cr−S system, the dimension of the Cr−S framework changes from 3D to 1D as the Ba/Cr ratio increases. 7 Compounds prepared under high pressure sometimes show interesting features. For example, Ba 3 CrS 5 is the first chromium(IV) sulfide and contains 1D chains composed of face-sharing CrS 6 octahedra, and BaCr 4 S 7 and Ba 2 Cr 5 S 10 contain unusual CrS 6 octahedra, which share their three faces with neighboring octahedra.…”

“…Therefore, the method is suitable for synthesis of new sulfides. For example, LnMS 3 (M = Ti, V, Cr; Ln = La, Ce, Nd, Sm) with the NH 4 CdCl 3 structure have been prepared at 2.5–5 GPa and 1375–1475 K. , We prepared the ternary chromium sulfides BaCr 4 S 7 (three-dimensional, 3D), Ba 2 Cr 5 S 10 (two-dimensional, 2D), Ba 3 CrS 5 (one-dimensional, 1D), and Ba 3 Cr 2 S 6 (1D) by high-pressure reactions, , where the dimension of the structure is given in parentheses. High-pressure synthesis allowed us to control the atomic ratios of the samples and enabled sulfur-rich phases to be obtained.…”

“…High-pressure synthesis allowed us to control the atomic ratios of the samples and enabled sulfur-rich phases to be obtained. In the Ba–Cr–S system, the dimension of the Cr–S framework changes from 3D to 1D as the Ba/Cr ratio increases …”

New Polymorph of Mo3S4 Prepared using a High-pressure Synthesis Technique: Crystal Structure, Electronic Property, and Band Calculation

“…29,30 In the previous studies, we succeeded in preparing four new chromium sulfides. 31,32 Their structures were solved and refined by X-ray single crystal analysis. Recently, interesting vanadium sulfides with a Cr 3 S 4 related structure have been prepared under high pressure by Klein et al 33 In the present study, we have successfully obtained the target compound Mo 3 S 4 , whose structure is closely related to that of Cr 3 S 4 .…”

Quaternary Layered Semiconductor Ba2Cr4GeSe10: Synthesis, Crystal Structure, and Thermoelectric Properties

“…The ternary Ba/Cr/S system is interesting; five known examples, BaCr 4 S 7 , Ba 2 Cr 5 S 10 , BaCrS 2 , Ba 3 Cr 2 S 6 , and Ba 3 CrS 5 , show their own structure types, which are, however, all built by the same CrS 6 tetrahedral primary building unit. More interestingly, as the Ba/Cr ratio increases, the dimensionality of these compounds decreases from 3D to 2D to 1D.…”