Shear strength measurements and hydrostatic compression of rhenium diboride under high pressures
Shear strength measurements and hydrostatic compression of rhenium diboride under high pressures
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DOI：
10.1063/5.0050057
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发表时间：
2021-05-28
影响因子：
3.2
通讯作者：
Vohra, Yogesh K.
中科院分区：
文献类型：
--
作者：
Burrage, Kaleb C.;Park, Changyong;Vohra, Yogesh K.
在金刚石压砧单元中，使用径向X射线衍射（R-XRD）技术，使用铂作为内部X射线压力标准，在74 GPa的压力下对二硼化铼ReB 2进行剪切强度测量。R-XRD的结果提供了一个独特的洞察六方晶格在非静水压力下的变形和剪切强度随压力的变化。根据R-XRD数据，我们已经估计了压缩的流体静力分量，以确定二硼化镁的状态方程，其产生的体积模量为K-0 = 366 +/-25GPa，压力导数K-0' = 4.3 +/-0.5，与流体静力密度泛函理论计算良好一致。然后使用测量的面间d-间距（dm）和d-间距的流体静力分量（dp）计算来自各种衍射平面的剪切强度（τ）的平均下限，以显示在70 GPa下接近6.7 +/-0.4 GPa。我们的研究结果表明，各向异性的压缩效应在ReB 2流体静力学压缩下观察到的相关的电子结构的变化，压缩下的理论计算预测。由AIP Publishing独家授权出版。
Shear strength measurements have been carried out on rhenium diboride, ReB2, to a pressure of 74 GPa using a Radial X-ray Diffraction (R-XRD) technique in a diamond anvil cell using platinum as an internal x-ray pressure standard. The R-XRD result has provided a unique insight into the deformation of hexagonal crystal lattice under non-hydrostatic compression and variation of shear strength with increasing pressure. From R-XRD data, we have estimated hydrostatic component of compression to determine an equation of state of rhenium diboride yielding a bulk modulus of K-0 = 366 +/- 25 GPa with a pressure derivative K-0' = 4.3 +/- 0.5 in good agreement with hydrostatic density functional theory calculations. The average lower bound of shear strength (tau) from various diffraction planes was then calculated using the measured interplanar d-spacing (dm) and hydrostatic component of d-spacing (dp) to be shown to approach 6.7 +/- 0.4 GPa at 70 GPa. Our results show that the anisotropic compression effects observed in ReB2 under hydrostatic compression are correlated to electronic structure changes under compression as predicted by theoretical calculations. Published under an exclusive license by AIP Publishing.