Iron dynamics in earth mantle minerals probed by Mössbauer spectroscopy using synchrotron radiation

探索地幔中铁矿物的动力学性质，可以在微观尺度上理解地震资料。Mössbauer光谱学是研究含铁矿物的电子和动力学性质的首选方法。因此，我们提出在高压同步辐射下，用Mössbauer光谱法测量含铁矿物橄榄石、辉石、硅酸钙钛矿和铁方长石的动态性质。采用密度泛函理论（DFT）的核非弹性散射（NIS）和伴随的量子力学模型计算将在实验和理论上提供所研究矿物状态的声子密度。这样我们就可以得到高压条件下这些材料中声速的信息。与NIS实验并行，我们将进行核正向散射（NFS），这将获得铁价态和相应的铁矿物相的信息。这在相变区域尤其有趣，相变是造成地幔地震响应不连续的原因。

Exploring the dynamic properties of iron minerals contained in the earth mantle enables to understand seismologic data on the microscopic scale. Mössbauer spectroscopy is the method of choice if electronic and dynamic properties of iron containing minerals have to be investigated. We therefore propose to measure the dynamic properties of the iron containing minerals olivine, pyroxene, iron silicate perovskite and ferropericlase by Mössbauer spectroscopy under high-pressure with synchrotron radiation. Nuclear inelastic scattering (NIS) and accompanying quantum mechanical model calculations employing density functional theory (DFT) will deliver the phonon density of states of the minerals under investigation both experimentally and theoretically. In this way we will obtain information on the velocity of sound in these materials under high pressure conditions. Parallel to the NIS experiments we will perform nuclear forward scattering (NFS) which will yield information on the iron valence state and the corresponding iron mineral phases. This is especially interesting in the region of phase transitions which are responsible for discontinuities in the seismic response of the earth mantle.