Diamond anvil cell measurement of high-pressure yield strength of vanadium using in situ thickness determination
Diamond anvil cell measurement of high-pressure yield strength of vanadium using in situ thickness determination
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DOI：
10.1103/physrevb.81.134107
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发表时间：
2010-04
影响因子：
3.7
通讯作者：
J. Klepeis;H. Cynn;W. Evans;R. Rudd;Lin H. Yang;H. Liermann;Wenge Yang
中科院分区：
文献类型：
--
作者：
J. Klepeis;H. Cynn;W. Evans;R. Rudd;Lin H. Yang;H. Liermann;Wenge Yang
在室温下，利用非静力金刚石顶锤技术，测量了多晶箔和粉末中钒的准静态屈服强度的压力依赖性，该技术是Meade和Jeanloz技术的扩展[C.Meade和R.Jeanloz，J.GePhys]。决议93,3261(1988)]。这项工作的一个特点是使用同步加速器X射线技术原位测定样品厚度和压力分布，从而确定样品上每个点的强度。在初始强度随压力增加之后，观察到钒的强度在大约40-50 GPa时开始下降。在最近的一次X射线衍射实验中，钒的屈服强度在高压下的软化是相当令人惊讶和不寻常的，此前在最近的一次X射线衍射实验中，与体心立方结构到菱面体结构的微妙相变相关的剪切模数异常软化的趋势。
The pressure dependence of the quasistatic yield strength of vanadium in polycrystalline foils and powders has been measured up to 90 GPa at room temperature using an implementation of a nonhydrostatic diamond-anvil cell technique, an extension of the technique of Meade and Jeanloz [C. Meade and R. Jeanloz, J. Geophys. Res. 93, 3261 (1988)]. A feature present in this work is the use of an in situ determination of the sample thickness and pressure profile using synchrotron x-ray techniques, allowing a determination of the strength at each point across the sample. Following an initial increase in the strength with pressure, a decrease in the strength of vanadium was observed starting at {approx}40-50 GPa. The softening of the yield strength of vanadium at high pressure is quite surprising and unusual, following the trend of an unusual softening of the shear modulus associated with a subtle phase transition from body-centered-cubic-to-rhombohedral structure in a recent x-ray diffraction experiment.