Boyang Zhao, Guodong Ren, Hongyan Mei, Vincent C Wu, Shantanu Singh, Gwan Yeong Jung, Huandong Chen, Raynald Giovine, Shanyuan Niu, Arashdeep S Thind, Jad Salman, Nick S Settineri, Bryan C Chakoumakos, Michael E Manley, Raphael P Hermann, Andrew R Lupini, Miaofang Chi, Jordan A Hachtel, Arkadiy Simonov, Simon J Teat, Raphaële J Clément, Mikhail A Kats, Jayakanth Ravichandran, Rohan Mishra
It is shown that structural disorder-in the form of anisotropic, picoscale atomic displacements-modulates the refractive index tensor and results in the giant optical anisotropy observed in BaTiS3 , a quasi-1D hexagonal chalcogenide. Single-crystal X-ray diffraction studies reveal the presence of antipolar displacements of Ti atoms within adjacent TiS6 chains along the c-axis, and threefold degenerate Ti displacements in the a-b plane. 47/49 Ti solid-state NMR provides additional evidence for those Ti displacements in the form of a three-horned NMR lineshape resulting from a low symmetry local environment around Ti atoms...
March 23, 2024: Advanced Materials