Interlaminar Fracture Toughness Measurement of Multilayered 2D Thermoelectric Materials Bi2Te3 by a Tapered Cantilever Bending Experiment
Interlaminar Fracture Toughness Measurement of Multilayered 2D Thermoelectric Materials Bi2Te3 by a Tapered Cantilever Bending Experiment
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DOI：
10.1007/s11340-021-00761-2
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发表时间：
2021-09
影响因子：
2.4
通讯作者：
Pan Wang;K. F. Wang;B. L. Wang;Li Xi;K. Sano;T. Shimada;H. Hirakata;D. Fang
中科院分区：
文献类型：
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作者：
Pan Wang;K. F. Wang;B. L. Wang;Li Xi;K. Sano;T. Shimada;H. Hirakata;D. Fang
背景多层热电材料碲化铋（Bi2Te3）因其优异的室温热电性能而在工程中得到广泛应用。然而，Bi2Te3由于其多层结构，容易出现裂纹、空隙或其他缺陷，导致器件寿命和可靠性下降。目的本文旨在稳定、精确地测量多层Bi2Te3的层间断裂韧性（IFT），用于Bi2Te3基热电器件的可靠性评估。此外，我们寻求一种即使对于非常脆的材料也能稳定测量 IFT 的方法。方法我们开发了锥形悬臂弯曲 (TCB) 实验来获得 IFT。使用聚焦离子束（FIB）技术在微观尺度上制造实验样本，并通过缺口法引入初始层间裂纹。结果通过进行TCB实验，我们创建了理想的尖锐预裂纹并观察到稳定的裂纹扩展。本文获得的裂纹扩展临界能量释放率 (ERR) 约为 0.51–0.53 J/m2，这与理论范德华 (vdW) 层间相互作用能相当一致。结论所提出的方法可以很好地应用于评估多层材料的 IFT，即使对于非常脆的多层二维材料也是如此。
BackgroundMultilayered thermoelectric material bismuth telluride (Bi2Te3) is widely used in engineering owing to its exceptional thermoelectric performance at room temperature. However, Bi2Te3is prone to cracks, voids, or other defects due to its multilayered structure, leading to decreased device lifetime and reliability.ObjectiveThis paper aims at stably and precisely measuring the interlaminar fracture toughness (IFT) of multilayered Bi2Te3for the reliability evaluation of Bi2Te3-based thermoelectric devices. In addition, we seek a method to stably measure the IFT even for very brittle materials.MethodsWe developed a tapered cantilever bending (TCB) experiment to obtain the IFT. The experimental specimens were fabricated using a focused ion beam (FIB) technique at the micro scale, and the initial interlaminar crack was introduced by the notch method.ResultsBy performing the TCB experiment, we created an ideally sharp pre-crack and observed stable crack propagation. The critical energy release rate (ERR) for crack propagation obtained in the present paper is around 0.51–0.53 J/m2, which agrees reasonably with theoretical van der Waals (vdW) interlaminar interaction energy.ConclusionsThe proposed method can be well-applied in assessing IFTs of multilayered materials, even for very brittle multilayered 2D materials.