Multifunctional Cu 2 TSiS 4 (T = Mn and Fe): Polar Semiconducting Antiferromagnets with Nonlinear Optical Properties

• Published in: Inorganic chemistry Vol. 62; no. 1; pp. 530 - 542
• Main Authors: Messegee, Zachary T, Cho, Jun Sang, Craig, Andrew J, Garlea, V Ovidiu, Xin, Yan, Kang, Chang-Jong, Proffen, Thomas E, Bhandari, Hari, Kelly, Jordan C, Ghimire, Nirmal J, Aitken, Jennifer A, Jang, Joon I, Tan, Xiaoyan
• Format: Journal Article
• Language: English
• Published: United States 09.01.2023
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.2c03754

Cu TSiS (T = Mn and Fe) polycrystalline and single-crystal materials were prepared with high-temperature solid-state and chemical vapor transport methods, respectively. The polar crystal structure (space group 2 ) consists of chains of corner-sharing and distorted CuS , Mn/FeS , and SiS tetrahedra, which is confirmed by Rietveld refinement using neutron powder diffraction data, X-ray single-crystal refinement, electron diffraction, energy-dispersive X-ray spectroscopy, and second harmonic generation (SHG) techniques. Magnetic measurements indicate that both compounds order antiferromagnetically at 8 and 14 K, respectively, which is supported by the temperature-dependent (100-2 K) neutron powder diffraction data. Additional magnetic reflections observed at 2 K can be modeled by magnetic propagation vectors = (1/2,0,1/2) and = (1/2,1/2,1/2) for Cu MnSiS and Cu FeSiS , respectively. The refined antiferromagnetic structure reveals that the Mn/Fe spins are canted away from the plane by about 14°, with the total magnetic moments of Mn and Fe being 4.1(1) and 2.9(1) μ , respectively. Both compounds exhibit an SHG response with relatively modest second-order nonlinear susceptibilities. Density functional theory calculations are used to describe the electronic band structures.