arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1502.01135cond-mat.mtrl-sci
收藏

从非晶相开始的拓扑绝缘体薄膜-以Bi $_2$ Se $_3$为例

Topological Insulator Thin Films Starting from the Amorphous Phase - Bi$_2$Se$_3$ as Example

J. Barzola-Quiquia, T. Lehmann, M. Stiller, D. Spemann, P. Esquinazi, P. Häussler

摘要:

提出了一种新的方法制备横向长度为厘米级的拓扑绝缘体Bi $_2$ Se $_3$薄膜。为了制备非晶Bi $_2$ Se $_3$薄膜,我们在室温下使用连续闪蒸方法。透射电子显微镜已被用来验证,所制备的样品是在一个纯的非晶态。在退火过程中,样品转变为菱方晶系的Bi $_2$ Se $_3$晶体结构,X射线衍射和拉曼光谱证实了这一点。的非晶薄膜的电阻测量显示预期的莫特可变范围跳跃导电过程中,具有高的电阻率相比,在结晶相(金属行为)中获得的。在2 ~ 275 K的温度范围内测量了样品的磁电阻(MR)和霍尔效应(HE)。在温度$T \lesssim 50$ K和磁场$B \lesssim 1$ T下,我们观察到MR中的弱反定域;霍尔测量证实了样品的n型特征。我们的薄膜的所有实验结果与使用更复杂的方法制备的样品的结果定量一致。

英文摘要:

We present a new method to obtain topological insulator Bi$_2$Se$_3$ thin films with a centimeter large lateral length. To produce amorphous Bi$_2$Se$_3$ thin films we have used a sequential flash-evaporation method at room temperature. Transmission electron microscopy has been used to verify that the prepared samples are in a pure amorphous state. During annealing the samples transform into the rhombohedral Bi$_2$Se$_3$ crystalline strcuture which was confirmed using X-ray diffraction and Raman spectroscopy. Resistance measurements of the amorphous films show the expected Mott variable range hopping conduction process with a high specific resistance compared to the one obtained in the crystalline phase (metallic behavior). We have measured the magnetoresistance (MR) and the Hall effect (HE) at different temperatures between 2 K and 275 K. At temperatures $T \lesssim 50$ K and fields $B \lesssim 1$ T we observe weak anti-localization in the MR; the Hall measurements confirm the n-type character of the samples. All experimental results of our films are in quantitative agreement with results from samples prepared using more sophisticated methods.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑