Charge Ordering Induced Ferromagnetic Insulator: K2Cr8O16
Charge Ordering Induced Ferromagnetic Insulator: K2Cr8O16
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DOI：
10.1103/physrevlett.104.256401
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发表时间：
2010-06-22
影响因子：
8.6
通讯作者：
Sarma, D. D.
中科院分区：
文献类型：
--
作者：
Mahadevan, Priya;Kumar, Abhinav;Sarma, D. D.
金属性通常伴随着铁磁性。K2Cr8O16是一种不太常见的磁性材料，在绝缘状态下表现出铁磁性。在第一性原理电子结构计算中分析电子和磁性，我们发现由于K的掺杂电子诱导了电荷有序和绝缘的基态，并且有趣的是还引入了Cr离子之间的铁磁耦合。发现驱动电荷排序的主要因素是静电因素，电荷定位在两个Cr原子上，使静电能量最小。伴随有序的结构扭曲产生了一个罕见的电荷有序驱动铁磁绝缘体的例子。
Usually metallicity accompanies ferromagnetism. K2Cr8O16 is one of the less common examples of magnetic materials, exhibiting ferromagnetism in the insulating state. Analyzing the electronic and magnetic properties within first principles electronic structure calculations, we find that the doped electrons due to K induce a charge-ordered and insulating ground state and interestingly also introduce a ferromagnetic coupling between the Cr ions. The primary considerations driving the charge ordering are found to be electrostatic ones with the charge being localized on two Cr atoms that minimize the electrostatic energy. The structural distortion that accompanies the ordering gives rise to a rare example of a charge-order driven ferromagnetic insulator.