Orientation Controlled Anisotropy in Single Crystals of Quasi-1D BaTiS3
Abstract
Low-dimensional materials with chain-like (one-dimensional) or layered (twodimensional) structures are of significant interest due to their anisotropic electrical, optical, thermal properties. One material with chain-like structure, BaTiS3 (BTS), was recently shown to possess giant in-plane optical anisotropy and glass-like thermal conductivity. To understand the origin of these effects, it is necessary to fully characterize the optical, thermal, and electronic anisotropy of BTS. To this end, BTS crystals with different orientations (aand c-axis orientations) were grown by chemical vapor transport. X-ray absorption spectroscopy (XAS) was used to characterize the local structure and electronic anisotropy of BTS. Fourier transform infrared (FTIR) reflection/transmission spectra show a large inplane optical anisotropy in the a-oriented crystals, while the c-axis oriented crystals were nearly isotropic in-plane. BTS platelet crystals are promising uniaxial materials for IR optics with their optic axis parallel to the c-axis. The thermal conductivity measurements revealed a thermal anisotropy of ~4.5 between the c- and a-axis. Time-domain Brillouin scattering showed that the longitudinal sound speed along the two axes is nearly the same suggesting that the thermal anisotropy is a result of different phonon scattering rates.
Keywords
Cite
@article{arxiv.2204.03680,
title = {Orientation Controlled Anisotropy in Single Crystals of Quasi-1D BaTiS3},
author = {Boyang Zhao and Md Shafkat Bin Hoque and Gwan Yeong Jung and Hongyan Mei and Shantanu Singh and Guodong Ren and Milena Milich and Qinai Zhao and Nan Wang and Huandong Chen and Shanyuan Niu and Sang-Jun Lee and Cheng-Tai Kuo and Jun-Sik Lee and John A. Tomko and Han Wang and Mikhail Kats and Rohan Mishra and Patrick E Hopkins and J. Ravichandran},
journal= {arXiv preprint arXiv:2204.03680},
year = {2024}
}