Determination of the Anisotropic Elastic Properties of Rocksalt Ge2Sb2Te5 by XRD, Residual Stress, and DFT

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• 作者：Raimondo Cecchini ; Krisztian Kohary ; Asunción Fernández ; Marcello Cabibbo ; Arnaud Marmier
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：March 17, 2016
• 年：2016
• 卷：120
• 期：10
• 页码：5624-5629
• 全文大小：328K
• ISSN：1932-7455

文摘

The chalcogenide material Ge<sub>2sub>Sb<sub>2sub>Te<sub>5sub> is the prototype phase-change material, with widespread applications for optical media and random access memory. However, the full set of its independent elastic properties has not yet been published. In this study, we determine the elastic constants of the rocksalt Ge<sub>2sub>Sb<sub>2sub>Te<sub>5sub>, experimentally by X-ray diffraction (XRD) and residual stress and computationally by density functional theory (DFT). The stiffnesses (XRD-stress/DFT) in GPa are C<sub>11sub> = 41/58, C<sub>12sub> = 7/8, and C<sub>44sub> = 8/12, and the Zener ratio is 0.46/0.48. These values are important to understand the effect of elastic distortions and nonmelting processes on the performances of increasingly small phase change data bits.