塞贝克系数
静水压力
电阻率和电导率
凝聚态物理
Crystal(编程语言)
抗磁性
物理
能量(信号处理)
材料科学
结晶学
热力学
化学
磁场
量子力学
计算机科学
程序设计语言
作者
Shuxiang Xu,Ziyi Liu,Pengtao Yang,Bin-Bin Ruan,Zhoupeng Ren,Jianping Sun,Yoshiya Uwatoko,B. S. Wang,Jinguang Cheng
出处
期刊:Physical review
日期:2024-04-17
卷期号:109 (14)
标识
DOI:10.1103/physrevb.109.144107
摘要
We report on crystal growth and physical properties of the quasi-one-dimensional compound ${\mathrm{Bi}}_{19}{\mathrm{S}}_{27}{\mathrm{I}}_{3}$ by combining crystal structure, electrical resistivity, magnetic properties, Seebeck coefficient, Hall coefficient as well as hydrostatic pressure effect up to 11.5 GPa. Unlike $p$-type ${\mathrm{Bi}}_{19}{\mathrm{S}}_{27}{\mathrm{I}}_{3}$ crystals, the maximum size of high-quality $n$-type ${\mathrm{Bi}}_{19}{\mathrm{S}}_{27}{\mathrm{I}}_{3}$ crystals can reach 2--3 mm by optimizing the chemical vapor transport method. The measurement results indicate that ${\mathrm{Bi}}_{19}{\mathrm{S}}_{27}{\mathrm{I}}_{3}$ is a diamagnetic semiconductor with two thermal activation energies, a large one ${E}_{\mathrm{g}1}\ensuremath{\sim}0.81$ eV and a small one ${E}_{\mathrm{g}2}\ensuremath{\sim}0.36$ eV, a huge room-temperature Seebeck coefficient of \ensuremath{-}1000 \textmu{}V/K, and improved thermoelectric power factor $\ensuremath{\sim}2.2\phantom{\rule{0.16em}{0ex}}\textmu{}\mathrm{W}\phantom{\rule{0.16em}{0ex}}\mathrm{c}{\mathrm{m}}^{\ensuremath{-}1}\phantom{\rule{0.16em}{0ex}}{\mathrm{K}}^{\ensuremath{-}2}$ owing to the enhanced electrical conductivity. Under pressure, ${\mathrm{Bi}}_{19}{\mathrm{S}}_{27}{\mathrm{I}}_{3}$ undergoes a semiconductor-to-metal transition, and the thermal activation energy continuously decreases to almost zero near a critical pressure of 4.25 GPa. Accompanying this process, a density-wave-like transition emerges, characterized by the reversible jump observed in the temperature dependence of the resistivity. As the pressure further increases, the resistivity undergoes a crossover from a Fermi metal to a low-temperature upturn below a characteristic temperature, which decreases from 81 K at 4.5 GPa to 37 K at 11.5 GPa. The upturn in resistivity has a linear dependence on the logarithmic temperature, but does not saturate at low temperatures, which basically excludes a Kondo-like state and indicates the possibility of Anderson weak localization. High-pressure synchrotron x-ray diffraction confirms the absence of structural transition for $P<12.05$ GPa at room temperature, supporting pressure-induced electronic transition. Our density functional theory calculation on the assumption that the Bi1 occupies an average of $\ensuremath{\sim}\frac{1}{6}$ contradicts experimental electron bands, indirectly indicating that Bi1 should be partially ordered and has many vacancies in ${\mathrm{Bi}}_{19}{\mathrm{S}}_{27}{\mathrm{I}}_{3}$. Our results provide good examples for studying the mechanism of semiconductor metallization and exploring thermoelectric functional properties in low-dimensional materials.
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