Mathon O, Baudelet F, Itié J-P, Pasternak S, Polian A, Pascarelli S
European Synchrotron Radiation Facility, BP 220, 38043 Grenoble CEDEX, France.
J Synchrotron Radiat. 2004 Sep 1;11(Pt 5):423-7. doi: 10.1107/S0909049504018862. Epub 2004 Aug 17.
The present paper demonstrates the feasibility of X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) at high pressure at the Fe K edge on the ID24 energy-dispersive beamline of the ESRF. In 3d transition metals, performing experiments at the hard X-ray K edge rather than at the magnetically interesting soft X-ray L edges represents the only way to access the high-pressure regime obtainable with diamond anvil cells. The simultaneous availability of a local structure (XAS) and of a magnetic (XMCD) probe on the sample under identical thermodynamical conditions is essential for studying correlations between local structural and magnetic properties. The state-of-the-art theoretical understanding of K-edge XMCD data is briefly summarized, and the set-up of beamline ID24 for high-pressure XMCD experiments is illustrated and the conditions required to perform measurements at the K edges of 3d transition metals are underlined. Finally, two examples of recent high-pressure results at the Fe K edge in pure Fe and Fe3O4 powder are presented.
本文展示了在欧洲同步辐射装置（ESRF）的ID24能量色散光束线上，在高压下于铁K边进行X射线吸收光谱（XAS）和X射线磁圆二色性（XMCD）实验的可行性。在3d过渡金属中，在硬X射线K边而非在具有磁学意义的软X射线L边进行实验，是进入使用金刚石对顶砧可实现的高压区域的唯一途径。在相同热力学条件下，同时具备对样品的局部结构（XAS）和磁性（XMCD）探测手段，对于研究局部结构与磁性性质之间的相关性至关重要。本文简要总结了对K边XMCD数据的最新理论理解，并说明了用于高压XMCD实验的ID24光束线设置，强调了在3d过渡金属K边进行测量所需的条件。最后，给出了在纯铁和Fe3O4粉末中铁K边的两个近期高压实验结果示例。
