Ding Yang, Haskel Daniel, Ovchinnikov Sergei G, Tseng Yuan-Chieh, Orlov Yuri S, Lang Jonathan C, Mao Ho-kwang
HPSynC, Carnegie Institution of Washington, 9700 South Cass Avenue, Argonne, Illinois 60439, USA.
Phys Rev Lett. 2008 Feb 1;100(4):045508. doi: 10.1103/PhysRevLett.100.045508.
Fe K-edge x-ray magnetic circular dichroism of magnetite (Fe3O4) powders was measured with synchrotron radiation under variable pressure and temperature conditions in diamond anvil cell. The magnetic dichroism was observed to decrease discontinuously by approximately 50% between 12 and 16 GPa, independent of temperature. The magnetic transition is attributed to a high-spin to intermediate-spin transition of Fe2+ ions in the octahedral sites and could account for previously observed structural and electrical anomalies in magnetite at this pressure range. The interpretation of x-ray magnetic circular dichroism data is supported by x-ray emission spectroscopy and theoretical cluster calculations.
在金刚石对顶砧池中可变压力和温度条件下，利用同步辐射测量了磁铁矿（Fe3O4）粉末的铁K边X射线磁圆二色性。观察到磁二色性在12至16吉帕之间不连续地下降约50%，与温度无关。这种磁转变归因于八面体位置上Fe2+离子的高自旋到中间自旋转变，并且可以解释此前在该压力范围内磁铁矿中观察到的结构和电学异常现象。X射线发射光谱和理论团簇计算支持了对X射线磁圆二色性数据的解释。
