High-pressure radial X-ray diffraction study of osmium to 58 GPa
High-pressure radial X-ray diffraction study of osmium to 58 GPa
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DOI：
10.1140/epjb/e2009-00436-4
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发表时间：
2010-02
期刊：
影响因子：
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通讯作者：
H. Chen;D. He;J. Liu;Y. Li;F. Peng;Z. Li;J. Wang;L. Bai
中科院分区：
文献类型：
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作者：
H. Chen;D. He;J. Liu;Y. Li;F. Peng;Z. Li;J. Wang;L. Bai
采用径向X射线衍射（RXRD）结合晶格应变理论，在金刚石压砧装置上研究了锇（Os）在58.2GPa压力下的非流体静力压缩行为。从RXRD数据得出的表观体积模量的Os从262 GPa到413 GPa变化，这取决于衍射平面相对于加载轴的取向。根据三阶Birch-Murnaghan状态方程拟合，在θ = 54.7°下得到的RXRD数据得到体积模量K 0 = 390 ± 6 GPa，压力导数K′ 0固定为4.在15.7- 58.2GPa压力范围内，差应力与剪切模量之比t/G在0.024 ~ 0.029之间。观察到屈服强度随着压缩而增加，并且在最高压力下达到11.7GPa的值。这证实了与所报道的刚性元素金属如W、Mo和Re相比，Os是已知最强的纯金属材料。实验发现，表观c/a比随非静液压缩和取向角的变化而变化。此外，在高压下的聚集体模量的Os测定从RXRD测量。
Nonhydrostatic compression behavior of osmium (Os) was investigated up to 58.2 GPa using radial X-ray diffraction (RXRD) together with lattice strain theory in a diamond-anvil cell. The apparent bulk modulus of Os derived from RXRD data varies from 262 GPa to 413 GPa, depending on Ψ, the orientation of the diffraction planes with respect to the loading axis. Fitting to the third-order Birch-Murnaghan equation of state, the RXRD data obtained at Ψ = 54.7° yields a bulk modulus K0= 390 ± 6 GPa with pressure derivative K′0fixed at 4. The ratio of differential stress to shear modulus t/G ranges from 0.024 to 0.029 at the pressures of 15.7–58.2 GPa. The yield strength was observed to increase with compression and reach the value of 11.7 GPa at the highest pressure. This confirms that Os is the strongest known pure metallic material compared with the reported stiff elemental metals such as W, Mo and Re. It was found that the apparent c/a ratio changed with the nonhydrostatic compression, as well as the orientation Ψ in our experiments. Moreover, the aggregate moduli of Os at high pressure were determined from the RXRD measurements.