Crystal Growth of Quaternary RE2EuSi2S8 (RE = Ce–Nd, Sm, Gd, Tb) Using Flux-Assisted Boron Chalcogen Mixture (BCM) Method: Investigation of Magnetic and Luminescence Properties
来源：ACS Publications
A series of quaternary rare-earth containing thiosilicates with the general formula RE2EuSi2S8 (RE = Ce–Nd, Sm, Gd, Tb) has been synthesized via the flux-assisted boron chalcogen mixture (BCM) crystal growth method. High-quality single crystals were obtained, and their crystal structures were determined by single-crystal X-ray diffraction. The RE2EuSi2S8 series crystallizes in the trigonal system, adopting the space group R-3c. Polycrystalline samples were employed for physical property measurements, including magnetic susceptibility measurements, UV–visible diffuse reflectance, and photoluminescent response. Magnetic data of RE2EuSi2S8 (RE = Ce, Nd, and Gd) were collected over the 2–300 K temperature range. The samples were paramagnetic behavior with negative Weiss constants (θW = −11.05, −10.55, and −1.35 K respectively). Their thermal stability was investigated using thermogravimetric analysis (TGA). Optical band gaps, estimated from diffuse reflectance spectra, were determined to be 2.2(1) eV for Ce2EuSi2S8, 1.8(1) eV for Nd2EuSi2S8, and 1.7(1) eV for Gd2EuSi2S8 respectively. Photoluminescence measurements were collected on Ce2EuSi2S8 and Tb2EuSi2S8 single crystals.