High Pressure Phase Of Ba2fes3: An Antiferromagnet With One-Dimensional Spin Chains

In this work, we report on the discovery of the high-pressure phase of Ba2FeS3 with quasi one-dimensional (1D) spin chains, which was synthesized under high-pressure and high-temperature conditions. A systematic study was carried out via structural, transport, magnetic and thermodynamic measurements. The high-pressure phase of Ba2FeS3 (denoted by Ba2FeS3 (HP)) crystallizes in a K2AgI3 typed orthorhombic structure with the space group of Pnma (62) and the lattice parameters of a = 8.6831 (1) angstrom, b = 4.2973 (1) angstrom, and c = 17.0254 (2) angstrom, respectively, which consists of chains of corner-sharing FeS4 tetrahedra along the b axis. Ba2FeS3 (HP) undergoes a long-range antiferromagnetic transition at T-N similar to 56 K, above which the magnetic susceptibility curve exhibits a round hump behavior with the maximum temperature T-max similar to 110 K. In addition, the intrachain coupling J(intra) is about -18 K obtained by using the Wagner-Friedberg model. The specific heat data suggest that the total magnetic entropy change AS caused by the long-range ordering transition is only similar to 20% of the expected value for a S = 2 system. For comparison, the properties of K2CuCl3-typed Ba2FeS3 with similar quasi 1D spin chains were presented as well. Our results indicate that both compounds exhibit a typical feature expected for compounds with 1D spin chains. (C) 2020 Elsevier B.V. All rights reserved.