Sound wave velocities of fcc Fe-Ni alloy at high pressure and temperature by mean of inelastic X-ray scattering
Sound wave velocities of fcc Fe-Ni alloy at high pressure and temperature by mean of inelastic X-ray scattering
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DOI：
10.1016/j.pepi.2007.06.006
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发表时间：
2007-09-14
影响因子：
2.3
通讯作者：
Dubrovinsky, Leonid S.
中科院分区：
文献类型：
--
作者：
Kantor, Anastasia P.;Kantor, Innokenty Yu.;Dubrovinsky, Leonid S.
镍含量低（5-25%）的铁镍合金的高压和高温弹性的知识对于地球科学至关重要，因为它可能是类地行星和月球核心的主要成分。在这里，我们提出了一个研究的FeNi合金与22原子。采用非弹性X射线散射（IXS）和多晶材料的X射线粉末衍射技术，对Ni在72 GPa和715 K下的热膨胀过程进行了研究。X-射线衍射（XRD）研究表明，在整个研究的压力-温度范围内的六方密堆积（hcp）相的面心立方（fcc）稳定。本文首次研究了铁镍合金Fe_（0.78）Ni_（0.22）面心立方相的弹性。在室温和715 K下，导出了等温状态方程（K-300 = 162（1）GPa，K '（300）= 4.97（1），V-300 = 6.89（1）cm（3）/mol; K-715 = 160（1）GPa，K'（715）= 4.97（2），V-715 = 6.96（1）cm（3）/mol）。非弹性X射线测量允许确定纵向声波速度V-p，并结合测量的状态方程提供材料的完全各向同性弹性。我们发现，在实验误差范围内，我们的数据遵循伯奇定律。我们没有观察到FeFe0.78Ni0.22与纯e-铁的弹性性质的任何显著偏差。(c)2007 Elsevier B.V保留所有权利。
Knowledge of the high-pressure and high-temperature elasticity of Fe-Ni alloy with low (5-25%) Ni content is crucial for geosciences since it is probably the major component of the cores of the terrestrial planets and the Moon. Here we present a study of a FeNi alloy with 22 at.% of Ni to 72 GPa and 715 K, using inelastic X-ray scattering (IXS) and X-ray powder diffraction from polycrystalline material. The X-ray diffraction (XRD) study revealed stability of the face centred cubic (fcc) over the hexagonal close packed (hcp) phase in the whole investigated pressure-temperature range. The study presents first investigations of elasticity of fcc phase of iron-nickel Fe0.78Ni0.22 alloy. The isothermal equations of state were derived at room temperature and at 715 K (K-300 = 162(1) GPa, K'(300) = 4.97(1), V-300 = 6.89(1) cm(3)/mol; K-715 = 160(1) GPa, K'(715) = 4.97(2), V-715 = 6.96(1) cm(3)/mol). Inelastic X-ray measurements allow the determination of the longitudinal acoustic wave velocity V-p, and provide, combined with the measured equations of state, the full isotropic elasticity of the material. We found that within experimental errors our data follow the Birch's law. We did not observe any significant deviations for fee Fe0.78Ni0.22 from elastic properties of pure e-iron. (c) 2007 Elsevier B.V All rights reserved.