Shon Won Hyuk, Rhyee Jong-Soo
Department of Applied Physics and Institute of Natural Sciences, Kyung Hee University, Yongin 446-701, Korea.
J Phys Condens Matter. 2015 Jan 21;27(2):025502. doi: 10.1088/0953-8984/27/2/025502. Epub 2014 Dec 19.
From the investigation of the electrical transport properties of single crystalline Bi(2-x)Sb(x)Se2Te (x = 0.0, 0.6, 0.8, 1.0, 1.2 and 1.4) compounds, we observed a systematic change of the Fermi level from n-type metallic (x = 0.0 and 0.6) or small-gap semiconducting (x = 0.8) to p-type semiconducting (x = 1.0) and metallic (x = 1.2 and 1.4), respectively, with increasing Sb-substitution concentration based on temperature-dependent electrical resistivity ρ(T) and Hall resistivity ρxy(H) measurements, respectively. The parent compound Bi2Se2Te exhibits linear negative magnetoresistance at low magnetic fields (H ⩽ 1 T) by weak localization. The intermediate doped compounds of x = 0.8 and 1.0 showed weak antilocalization (WAL) and weak localization (WL) crossover behavior from the field-dependent magnetoresistance measurements at low temperatures. From the Hikami-Larkin-Nagaoka analysis of the compounds (x = 0.8 and 1.0), we found that there is a competing behavior between WL and WAL in terms of Sb-doping and magnetic field strength.
通过对单晶Bi(2 - x)Sb(x)Se2Te（x = 0.0、0.6、0.8、1.0、1.2和1.4）化合物的电输运性质进行研究，基于对温度依赖的电阻率ρ(T)和霍尔电阻率ρxy(H)的测量，我们分别观察到随着Sb替代浓度的增加，费米能级发生了系统性变化，从n型金属（x = 0.0和0.6）或小间隙半导体（x = 0.8）分别转变为p型半导体（x = 1.0）和金属（x = 1.2和1.4）。母体化合物Bi2Se2Te在低磁场（H ⩽ 1 T）下通过弱局域化表现出线性负磁阻。x = 0.8和1.0的中间掺杂化合物在低温下的场依赖磁阻测量中显示出弱反局域化（WAL）和弱局域化（WL）的交叉行为。通过对化合物（x = 0.8和1.0）的日高 - 拉金 - 长冈分析，我们发现在Sb掺杂和磁场强度方面，WL和WAL之间存在竞争行为。
